Quantum Computing and Information

The emerging field of quantum machine learning has the potential to substantially aid in the problems and scope of artificial intelligence. This is only enhanced by recent successes in the field of classical machine learning. In this work we propose an approach for the systematic treatment of machine learning, from the perspective of quantum information. Our approach is general and covers all three main branches of machine learning: supervised, unsupervised, and reinforcement learning. While quantum improvements in supervised and unsupervised learning have been reported, reinforcement learning has received much less attention. Within our approach, we tackle the problem of quantum enhancements in reinforcement learning as well, and propose a systematic scheme for providing improvements. As an example, we show that quadratic improvements in learning efficiency, and exponential improvements in performance over limited time periods, can be obtained for a broad class of learning problems.

A superluminal quantum-vortex model of the electron and the positron is produced from a superluminal double-helix model of the photon during electron-positron pair production. The two oppositely-charged (with Q = ±e sqrt (2/α) = 16.6e) open-helix spin-½ half-photons compose the double-helix photon. These half-photons separate and curl up their separated superluminal single-helical trajectories to form an electrically-charged superluminal closed-helix spin-½ quantum-vortex electron model and a corresponding positron model. The helical radius and the Dirac equation's zitterbewegung angular frequency of the quantum vortex electron and positron models equal the helical radius and zitterbewegung angular frequency of the two spin-½ half-photons, each of energy E = mc^2 , that composed the double-helix photon model of energy E = 2mc^2 from which the electron and positron models were produced. The photon and electron models are also compatible when a photon of energy E > 2mc^2 produces a relativistic electron-positron pair. Implications of the quantum vortex electron model for electron stability are discussed.

STRESZCZENIE Urządzenie kwantowe NISQ działa w praktyce bez zaawansowanych metod korekcji błędów kwantowych (QEC). Takiej korekcji nie można wprowadzić sprzętowo ze względu na skromność układu NISQ. Komputer UQC musi koniecznie posiadać złożone warstwy korekcji błędów na poziomach sprzętowym i programistycznym. Bez warstw QEC komputer UQC nie ma możliwości wypełnienia swoich zadań obliczeniowych. Niestety wiele z metod QEC jest silnie redundancyjnych, a więc bardzo kosztownych. Komputer UQC, mimo że dość dobrze znamy jego potencjalne właściwości, jest urządzeniem teoretycznym, w związku z czym badania nad QEC odbywają się w warstwie coraz bardziej zaawansowanych technik symulacyjnych prowadzonych oczywiście w przestrzeni komputingu klasycznego. Pewne, na razie bardzo niewielkie, możliwości eksperymentalne oferuje urządzenie NISQ. Techniki QEC definiuje się najczęściej jako specjalizowane metody stosowane w zaszumionym, rzeczywistym nieidealnym komputingu kwantowym w celu zabezpieczenia informacji kwantowej przed dekoherencją i szumem kwantowym. Równie często QEC jest stosowany do zabezpieczenia informacji w komunikacji kwantowej, gdzie stany kwantowe są transmitowane przez zaszumiony kanał kwantowy. QEC jest częścią szerszego obszaru projektowania systemu kwantowego odpornego na błędy. Inne podejścia do mitygacji błędów w systemach kwantowych zawierają: podprzestrzenie bez dekoherencji, podsystemy bezszumne, dynamiczne odsprzężenie od środowiska termodynamicznego.

Quantum superposition is a fundamental principle of quantum
mechanics, and in quantum information techniques it is the
fundamental space for the existence of a qubit, two-level energy
quantum system, and its more general form, multi-level energy
quantum system, a qudit. Two fundamental / basis / pure quantum
states of a qubit can be added together, superposed, coexist
simultaneously, and the result is a different quantum state of this
qubit. Each quantum state of a qubit can be represented as the
sum of two different quantum states. Each qudit quantum state
can be represented as the sum of many different quantum states.
Coherence is an essential category for a qubit to be in superposition.
Quantum coherence (and the associated interference)
and entanglement are, in a sense, co-rooted in the principle of
quantum superposition. Coherence and quantum entanglement
are categories in terms of resources and operationally related,
although conceptually and ideologically different. The resource
approach to these categories uses interchangeable quantitative
and qualitative measures, allowing for an analogous assessment
of the functional capabilities of quantum computational and metrological
systems remaining in a state of superposition, through
the resources of coherence and entanglement stored in them.
Quantum superposition is a kind of a basement foundation, on
which measurable qualitatively and quantitatively resources like
coherence and entanglement enable building quantum technologies
and applications. There are numerable measures for these
quantum resources, simpler for pure quantum states and more
complex for mixed states. These measures see the resources
from different functional states. There are defined other measures
especially for mixed quantum states like the quantum discord.

For a long time, one of my dreams was to describe the nature of uncertainty axiomatically, and it looks like I've finally done it in my co∼eventum mechanics! Now it remains for me to explain to everyone the co∼eventum mechanics in the most approachable way. This is what I'm trying to do in this work. The co∼eventum mechanics is another name for the co∼event theory, i.e., for the theory of experience and chance which I axiomatized in 2016 [1, 2]. In my opinion, this name best reflects the co∼event-based idea of the new dual theory of uncertainty, which combines the probability theory as a theory of chance, with its dual half, the believability theory as a theory of experience. In addition, I like this new name indicates a direct connection between the co∼event theory and quantum mechanics, which is intended for the physical explanation and description of the conict between quantum observers and quantum observations [4]. Since my theory of uncertainty satises the Kolmogorov axioms of probability theory, to explain this co∼eventum mechanics I will use a way analogous to the already tested one, which explains the theory of probability as a theory of chance describing the results of a random experiment. The simplest example of a random experiment in probability theory is the " tossing a coin ". Therefore, I decided to use this the simplest random experiment itself, as well as the two its analogies: the " "flipping a coin " and the " spinning a coin " to explain the co∼eventum mechanics, which describes the results of a combined experienced random experiment. I would like to resort to the usual for the probability theory " coin-based " analogy to explain (and first of all for myself) the logic of the co∼eventum mechanics as a logic of experience and chance. Of course, this analogy one may seem strange if not crazy. But I did not come up with a better way of tying the explanations of the logic of the co∼eventum mechanics to the coin-based explanations that are commonly used in probability theory to explain at least for myself the logic of the chance through a simple visual " coin-based " model that clarifies what occurs as a result of a combined experienced random experiment in which the experience of observer faces the chance of observation. I hope this analogy can be useful not only for me in understanding the co∼eventum mechanics.

We utilize the principles of quantum computing to explore and discuss the possibilities of quantum supremacy: by using the QUBIT4MATLAB package, we created a quantum circuit implementation of the quantum Fourier transform alongside an implementation of the radix-2 DIT case of the Cooley-Tukey Algorithm. We also compare and contrast our simulated rendition of the QFT with the theoretical, ideal rendition of the QFT. Through complexity analysis and the use of the Master Theorem, we find that: (1.) our DFT implementation is of complexity O(N log N); (2.) our simulation of the QFT is of complexity O(N 2) and (3.) the complexity of the theoretical (computationally ideal) version of the QFT is O(log 2 N). While our theoretical QFT complexity may appear to triumph over the classical DFT, we find that these results continue to support the current ambivalence of quantum supremacy.

Partial trace is a very important mathematical operation in quantum mechanics. It is not only
helpful in studying the subsystems of a composite quantum system but also used in computing
a vast majority of quantum entanglement measures. Calculating partial trace becomes computationally
very intensive with increasing number of qubits as the Hilbert space dimension increases
expotentially. In this paper we discuss about our new method of partial tracing called the combinatorial
method of partial tracing which is more faster and accurate than the existing methods
of partial tracing. The combinatorial method of partial tracing overcomes all the limitations of
the other well known methods such as being computationally intensive and being limited to low
dimensional Hilbert spaces. We give a detailed theoretical description of our method and also
provide an explicit example of the computation. The merits of the new method and other key
ideas are discussed.

Questo elaborato offre una rassegna dei principi che sottendono alla computazione quantistica. Introdurremo alcuni risultati di algebra linea-re e meccanica quantistica indispensabili a quanto segue. Presenteremo un particolare formalismo, ossia i quantum gate array, per modellare la computazione quantistica. Infine, concluderemo con la descrizione di uno dei primi algoritmi quantistici creati da David Deutsch e Richard Jozsa nel 1992.

In this Book is an overview of Quantum Information Systems is given. Therefore, the postulates of quantum mechanics are given based on one interpretation that is called the Copenhagen interpretation. The main pillars of quantum mechanics are: Superposition, Interference, and Entanglement. Quantum Information Systems comprise three disciplines: Quantum Computation, Quantum Communication, and Quantum Control. Each one of them has a number of topics with some implementations that have reached the commercial level. Quantum Computation has three models: the circuit model that is using different techniques like superconducting elements and special Silicon-based elements. The Adiabatic quantum model has reached the commercial stage through a start-up company using superconducting chips. The categorical quantum model is based on category theory and one of its main applications is the study and verification of network and cryptographic protocols. Quantum communication started with defining the basic unit of information, the qubit. Then the quantum compression theorem was proved. The quantum channel capacity problem was divided into two problems: transmitting classical information over a quantum channel, and transmitting quantum information over a quantum channel. The first problem was partially resolved. However, the second problem is being researched upon. Two applications will be briefly presented: quantum teleportation and superdense coding. Both of them employs quantum entanglement. Quantum Key Distribution (QKD) using cryptographic protocols has received much attention due its importance in network security. A number of protocols have been proposed and some of them have been implemented, and now a number of commercial products have been announced. Also, some experimental networks have been implemented. QKD using space links have been proposed and experimented with. In few years quantum satellites will be launched. Quantum cryptographic protocols are being proposed to protect infrastructure networks like the electric power grid. Also, it is being used as a countermeasure against global spying networks like ECHELON that are detrimental for national economies. The Quantum Internet is also being considered using quantum teleportation together with Cavity Quantum Electrodynamics with some experimental work going on. Quantum Control is essential for both Quantum Computation and Quantum Communication. Intensive research is going on in: State estimation (called Quantum State Tomography), system identification (called Quantum Process Tomography), and Quantum Feedback Control. The basic concepts will be briefly considered in this presentation. University education has witnessed major changes to support the above developments. At the postgraduate level many universities offer many courses related to the above disciplines. Recently, a number of institutions started to offer undergraduate courses and some of them have even started to introduce Quantum Engineering 4 years undergraduate programs. A brief account will be given to such developments.

Quantum Internet is a term that is already used today, though
probably exaggerated, in quantum information techniques. It is
an irresistible temptation to simply replace all the elements of the
current global network with components with the adjective quantum. Hosts, servers, modems, hubs, network bridges and switches,
network cards and many other devices, software, protocols, etc.
must be quantum. Unfortunately, this is not the case and the road
to such a state is quite distant. Another approach, also distant
from practical implementation, is a completely new design of the
concept of a quantum network based not on a classical topology
but on a potential topology allowing the distribution of only what
is most important, i.e., quantum resources, in particular nonlocal
resources. There are several concepts for building the quantum
Internet, and the simplest method is to follow well-trodden paths.
To implement such the simplest quantum Internet, you need,
among others, quantum memories, quantum repeaters, stationary
qubit converters to flying qubits and vice versa, etc. The European
Union promotes development in this direction by creating thematic
pillars, eg. Digital Europe within the framework programs, previously H2020 and now Horizon Europe. The European Quantum
Flagship EQF, the OpenQKD Quantum Key Distribution Environment, the QIA Quantum Internet Alliance, the EuroQCI European
Quantum Communication Infrastructure are examples of such
initiatives

Fundamental quantum no-go theorems are related to the principles
of conservation of energy in a closed system, the Pauli exclusion
principle and the spin-statistics theorem, the Heisenberg uncertainty
principle, the exclusion of superluminal velocity, the black hole
information paradox, its evaporation and the only three-parameter
description with mass, electric charge and angular momentum, quantum
determinism and time reversibility (CPT symmetry), continuous
multichannel coupling of the quantum micro world with the thermodynamic
macro world manifested by the dynamics of decoherence
selection rules, etc. The available building blocks are qubits, kudits,
gates and circuits, quantum memories, etc. The general signal resource
in IQT is nonlocality, the possibility of its harnessing at the technical
level, and its potential quantitative and qualitative assessment,
often related to the LOCC level. In particular, not entirely equivalent
resources are quantum discord, contextuality, quantum entropy, and
most often the entanglement. The tools for building IQT are quantum
teleportation, quantum tomography, entangled states sharing, control
of physical and logical qubits, qubit virtualization, entanglement
distillation, correction of quantum errors, transfer of quantum states
between stationary and flying qubits, etc. The goal is to build a quantum
Internet, ultimately entirely quantum, and currently in the NISQ v
ersion.

This paper is written by a group of Ph.D. students
pursuing their work in different areas of ICT, outside the direct
area of Information Quantum Technologies IQT. An ambitious
task was undertaken to research, by each co-author, a potential
practical influence of the current IQT development on their
current work. The research of co-authors span the following areas
of ICT: CMOS for IQT, QEC, quantum time series forecasting,
IQT in biomedicine. The intention of the authors is to show how
quickly the quantum techniques can penetrate in the nearest
future other, i.e. their own, areas of ICT.

Inseparable metasyntactic objects, variables Alice and Bob, together with their wider companionship, enter the quantum world from
the classical world. They must notice that there is a big difference
between these worlds, but there are also similarities. Aliases (vel)
are anthropomorphising of devices or software that perform appropriate activities necessary to implement the most often secure
communication and calculations in ICT systems and networks.
These aliases for archetypes in cryptology were conceived by the
creators of the RSA public key asymmetric cryptographic algorithm
in 1978. From this historic point in time, Alice and Bob have matured significantly with the advancement of technology. Despite
this development, the RSA algorithm, which uses the difficulty of
factorization of large complex numbers, is still the most popular in
cryptography. So, what special privileges do Alice and Bob get in
the world of cryptography and quantum computing, as researchers
are already working on the development of post-quantum cryptography and security? Do Alice and Bob have anything to be afraid of?
Peter Shor’s quantum probabilistic algorithm enables the factorization of a complex natural number N over polynomial time O [(logN)3
]
using the O (log N) memory. The classical algorithm factorizing
the number N in logarithmic time O [(logN) k] for any k is unknown.
Quantum systems for the Shor’s algorithm implementation are
optimized in terms of memory use and operating time towards
increasing computational efficiency. Progress in the field of simulation-optimized quantum processor architectures still needs to
be put into practice, which is quite difficult at present. Alice and
Bob remain today much safer in the classical world. For how long?

The following lecture notes are based on the book Quantum Computation and Quantum Information by Michael A. Nielsen and Isaac L. Chuang. They are for a math-based quantum computing course that I teach here at the University of Washington to computer science graduate students (with advanced undergraduates admitted upon request). These notes start with a brief linear algebra review and proceed quickly to cover everything from quantum algorithms to error correction techniques. The material takes approximately 16 hours of lecture time to present. As a service to educators, the L A T E Xand Xfig source to these notes is available online from my home page: http://www.cs.washington.edu/homes/oskin. In addition, under the section " course material " from my web page, in the spring quarter/2002 590mo class you will find a sequence of homework assignments geared to computer scientists. Please feel free to adapt these notes and assignments to whatever classes your may be teaching. Corrections and expanded material are welcome; please send them by email to oskin@cs.washington.edu.

Quantum Nano science is the research area and the branch of nanotechnology and physics that uses
methods of quantum mechanics to the design of new types of Nano devices and Nano scale materials, where functionality and structure of quantum Nano devices are described through quantum phenomena and principles such as discretization, superposition and entanglement

This conceptual research proposes a quantum communication intelligence chain (QCIC) cardinal symbiotic model composed of-Integrant Technologies‖ that are unsung heroes integrating quantum computing, 5G wireless communication, artificial intelligence, and blockchain transforming industries from all business sectors creating the impact to spur market growth and the global economy in the 21 st century.A comprehensive analysis of integrant technological developmental endeavors in the field of quantum computing, 5G (fifth generation) mobile communication, artificial intelligence, and blockchain are offered to ensure the futuristic synergetic systems thinking that are going to provide evolutionary and revolutionary applications in the years to come. The author applies exhaustive literature review, system thinking methodology, and a case study (Inditex Group) of the fashion industrythat focus on delivering the best possible evidence-based research and perspective on QCIC design applications. The contribution of this research provides the essential principles of systems thinking design with the QCIC innovation as "holistic and interdisciplinary" approach forthe transformation of value chain to overcome competition to attain design transcendence and stakeholder satisfaction creating sustainable value co-creation.This study provides precept to various industry practitioners, non-government organizations (NGOs), academia, entrepreneurs, investors, and policymakers to assuage economic benefit setting the stage for exciting new devices and services in the years ahead. Future researchers can build on QCIC systems thinking to examine the limitations of this model by using empirical researches. INTRODUCTION The future will be elucidated by advances in quantum computing, quantum machine learning, cloud computing, blockchain, artificial intelligence, autonomous IoT (AIoT), big data analytics, and augmented/virtual reality supported by 5G enhanced broadband, low-latency, secure wireless connectivity. When one experience 5G wireless communication, the operating speed will be at the speed of light.

Open source software is becoming crucial in the design and testing of quantum algorithms. Many of the tools are backed by major commercial vendors with the goal to make it easier to develop quantum software: this mirrors how well-funded open machine learning frameworks enabled the development of complex models and their execution on equally complex hardware. We review a wide range of open source software for quantum computing, covering all stages of the quantum toolchain from quantum hardware interfaces through quantum compilers to implementations of quantum algorithms, as well as all quantum computing paradigms, including quantum annealing, and discrete and continuous-variable gate-model quantum computing. The evaluation of each project covers characteristics such as documentation, licence, the choice of programming language, compliance with norms of software engineering, and the culture of the project. We find that while the diversity of projects is mesmerizing, only a few attract external developers and even many commercially backed frameworks have shortcomings in software engineering. Based on these observations, we highlight the best practices that could foster a more active community around quantum computing software that welcomes newcomers to the field, but also ensures high-quality, well-documented code.

The largest number factored on a quantum
device reported until now was 143. That quantum computation, which used only 4 qubits at 300K, actually also factored much larger numbers such as 3599, 11663, and 56153, without the awareness of the authors of that work. Furthermore, unlike the implementations of Shor’s algorithm performed thus far, these 4-qubit factorizations do not need to use prior knowledge of the answer. However, because they only use 4 qubits, these factorizations can also be performed
trivially on classical computers. We discover a class of numbers for which the power of quantum information actually comes into play. We then demonstrate a 3-qubit factorization of 175,
which would be the first quantum factorization of a triprime.

This work addresses Lindbladians admitting attractive subspaces in which time evolution is exclusively unitary. Such subspaces can be used to store, protect, and process quantum information. We derive an analytical formula for the left eigenmatrices of such Lindbladians corresponding to pure imaginary eigenvalues. This formula resolves how Lindbladian evolution affects the perturbative response and geometrical features of the attractive subspaces. We show that all Hamiltonian and certain jump operator perturbations induce (to first order) exclusively unitary evolution on the subspaces. Similarly, the holonomy induced on such subspaces after (adiabatic) traversal of a closed path in the parameter space is unitary. We derive a new Riemannian metric tensor in the parameter space induced by a large family of attractive subspaces. The adiabatic curvature (related to holonomies) and the metric tensor (related to the path length) are shown to be parts of a Lindblad quantum geometric tensor, generalizing this structure to Lindbladians possessing one or more mixed steady states. We derive a Kubo formula governing linear response of the attractive subspaces to Hamiltonian perturbations and determine cases in which this formula reduces to a Hamiltonian-based Kubo formula. As an application, we show that (for gapped systems) the zero-frequency Hall conductivity is unaffected by many types of Markovian dissipation. Finally, we show that the energy scale governing leakage out of the attractive subspaces, resulting from either corrections to adiabatic evolution or Hamiltonian perturbations, is different from the conventional Lindbladian dissipative gap. In certain cases, this scale is equivalent to the excitation gap of a related Hamiltonian. We summarize our key results by introducing "four-corners" notation and presenting two properties of generic subspaces, the "no-leak" and "clean-leak" properties.

The logic of uncertainty is not the logic of experience and as well as it is not the logic of chance. It is the logic of experience and chance. Experience and chance are two inseparable poles. These are two dual reflections of one essence, which is called co∼event. The theory of experience and chance is the theory of co∼events. To study the co∼events, it is not enough to study the experience and to study the chance. For this, it is necessary to study the experience and chance as a single entire, a co∼event. In other words, it is necessary to study their interaction within a co∼event. The new co∼event axiomatics and the theory of co∼events following from it were created precisely for these purposes. In this work, I am going to demonstrate the effectiveness of the new theory of co∼events in a studying the logic of uncertainty. I will do this by the example of a co∼event splitting of the logic of the Bayesian scheme, which has a long history of fierce debates between Bayesionists and frequentists. I hope the logic of the theory of experience and chance will make its modest contribution to the application of these old dual debaters.

Keywords: Eventology, event, probability, probability theory, Kolmogorov’s axiomatics, experience, chance, cause, consequence, co∼event, set of co∼events, bra-event, set of bra-events, ket-event, set of ket-events, believability, certainty, believability theory, certainty theory, theory of co∼events, theory of experience and chance, co∼event dualism, co∼event axiomatics, logic of uncertainty, logic of experience and chance, logic of cause and consequence, logic of the past and the future, Bayesian scheme.

Contextuality in human cognition can be defined as the existence of thoughts that are locally consistent and globally inconsistent. Absence of contextuality in the representational theories that are used for modelling cognitive processes results in inconsistencies between expected and actual decisions. These inconsistencies are usually regarded as paradoxes. However, recent literature reports that the quantum formalism is successful in explaining these paradoxes. In this article, we show the remarkable connection between contextuality, cognitive paradoxes and quantum formalism with a focus on decision-making. In this regard, we first analyse the paradoxes of human cognition from contextuality perspective as they share the pattern of local consistency and global inconsistency. This analysis is carried out using the proposed two-step contextuality analysis framework using the theories such as contextuality-by-Default and State Context Property formalism. Subsequently, this analysis provides an understanding on the dynamics of thoughts that has led to the paradoxical decisions which varies from the theoretical decisions. On the other hand, the success of quantum approach to cognitive paradoxes is due to their support for contextuality which is facilitated by the natural quantum characteristics. In this regard, we also narrate on how natural quantum characteristics facilitate contextuality with an example on decision-making. As a result, this article brings out the importance of contextuality in cognitive paradoxes and quantum formalism. Inferences obtained from this analysis emphasize on how and why quantum formalism is suitable for cognitive paradoxes. Our contribution stands out from the literature due to its comprehensive nature.

"It has become increasingly apparent that a number of perplexing issues associated with the interpretation of quantum mechanics are more easily resolved once the notion of retrocausality is introduced. The aim here is to list and discuss various examples where a clear explanation has become available via this approach. In so doing, the intention is to highlight that this direction of research deserves more attention than it presently receives."
Written by Roderick Sutherland, whose formalism is the basis for the solution of the "hard problem" i.e. physical explanation of consciousness and the nano-electronic technology it makes possible.

A quantum processor controlled by classical instructions is modeled. The processor follows the quantum random access machine (QRAM) model: a quantum memory and a quantum ALU (qALU) containing a group of quantum gates, which are controlled by classical signals. The processor's instructions are written using a quantum assembly (QASM) language. As test cases, several well-known quantum circuits are described using the QASM language and executed by our model. This model may later be integrated with classical components to form a hybrid quantum computer.

STRESZCZENIE Informacja kwantowa, której jednostką elementarną jest kubit, jest zawarta w skwantowanym, dyskretnym stanie układu kwantowe-go. Od informacji klasycznej odróżnia ją charakter probabilistyczny oraz możliwość zakodowania w nielokalnych związkach pomię-dzy układami kwantowymi. Kwantowe związki nielokalne, będące powszechną właściwością wszechświata, nazywamy stanami splątanymi. Układ kwantowy jest obiektem podlegającym mecha-nice kwantowej i jest ograniczony rozmiarowo do skali atomowej� Kubit jest dowolną superpozycją dwóch stanów kwantowych oznaczanych jako |0> i |1>. Odczytując wartość kubitu uzyskuje się z pewnym prawdopodobieństwem wartość 0 lub 1. Nie można przewidzieć która wartość zostanie odczytana. Stan układu kwan-towego jest nietrwały, ograniczony przez czas dekoherencji. Czas ten, zdeterminowany szumem i właściwościami układu odczytu, ogranicza skalowalność technologii kwantowych. Kubitem są np. elektron i jego dwuwartościowy spin, foton i jego dwuwartościowy stan polaryzacji, jon z odpowiednio wybranymi dwoma pozioma-mi energetycznymi, ale też molekuły posiadające spin, oscylatory kwantowe czy kwazicząstki. Rejestr kwantowy jest uporządkowa-nym układem kubitów. Z kubitów i ich układów buduje się logiczne bramki kwantowe. Z kubitów, bramek kwantowych i układów kontro-lno-sterujących buduje się systemy kwantowe: komputery, zegary, czujniki, systemy pomiarowe, urządzenia, grawimetry, akcelerome-try i wiele innych� Do kontroli kubitów potrzeba jest zaawansowana ABSTRACT Quantum information, the unit of which is a qubit, is contained in a quantized, discrete state of a quantum system� What distinguishes it from classical information is its probabilistic nature and the possibility of coding it in non-local relationships between quantum systems� Quantum nonlocal relationships, a common feature of the universe, are called entangled states� A quantum system is an object subject to quantum mechanics and is limited in size to the atomic scale� A qubit is an arbitrary superposition of two quantum states marked as |0> and |1>� When you read the value of a qubit, you get a value of 0 or 1 with some probability� You cannot predict which value will be read� The state of the quantum system is unstable, limited by the time of decoherence� This time, determined by noise and properties of the readout system, limits the scalability of quantum technologies� The qubit is an electron and its bivalent spin, a photon and its bivalent polarization state, an ion with two suitably selected energy levels, but also molecules with spin, quantum oscillators or quasiparticles� A quantum register is an ordered system of qubits� Logical quantum gates are built from qubits and their systems� Quantum systems are built from qubits, quantum gates and measurement and control systems: computers, clocks, sensors, measuring systems, devices, gravimeters, accelerometers, and many others� To control qubits, you need advanced photonics, ultra-stable tuneable single-frequency lasers, and advanced, preferably standardized electronics� KEYWORDS: quantum information, quantum information technology, two-level quantum system, qubit, quantum gate, quantum register, quantum state, quantum computer, quantum sensor,

We present a full-fledged, highly-optimized, constant-time software for post-quantum supersingular isogeny-based undeniable signature (SIUS) on the ARMv8 platforms providing 83- and 110-bit quantum security levels. To the best of our knowledge, this work is the first empirical implementation of isogeny-based quantum-resistant undeniable signature presented to date. The proposed software is developed on the top of our optimized hand-written ARMv8 assembly arithmetic library and benchmarked on a variety of platforms. The entire protocol runs less than a second on Huawei Nexus smart phone, providing 83-bit quantum security level. Moreover, our signature and public key sizes are 25% smaller than the original SIUS scheme. We remark that the SIUS protocol, similar to other isogeny-based schemes, suffers from the excessive number of operations, affecting its overall performance. Nonetheless, its significantly smaller key and signature sizes make it a promising candidate for post-quantum cryptography.

The largest number factored on a quantum device reported until now was 143. That quantum computation, which used only 4 qubits at 300K, actually also factored much larger numbers such as 3599, 11663, and 56153, without the awareness of the authors of that work. Furthermore, unlike the implementations of Shor's algorithm performed thus far, these 4-qubit factorizations do not need to use prior knowledge of the answer. However, because they only use 4 qubits, these factorizations can also be performed trivially on classical computers. We discover a class of numbers for which the power of quantum information actually comes into play. We then demonstrate a 3-qubit factorization of 175, which would be the first quantum factorization of a triprime.

A logical qubit is a real or virtual, software-based quantum system
that performs the functions of a single physical qubit. It usually
consists of many or large number of physical qubits, or single
models/symbols of physical qubits. In an ideal quantum gate
system, in principle, a logical qubit might be unnecessary. All
quantum operations can be performed by a system of single-qubit
and double-qubit gates, eg CX and I-H. Multi-qubit gates, eg CCX,
Toffoli, etc., can be introduced to reduce the topology of the system and shorten the length of the quantum wires connecting the
gates. Hardware and software redundant logical qubits are being
introduced as the now necessary intermediate step, idealizing, but
only to a certain extent, noisy physical qubits and their imperfect
working conditions/environment. Logical qubits can be convenient
for building quantum software at the logical level, optimizing the
topology and functionality of quantum gate systems, mitigating
quantum errors, and virtualizing quantum systems/networks. The
cost of introducing logical qubits is increased resource consumption. Logical qubits are used practically and theoretically in quantum computing circuits. In future universal quantum computers
UQC the logical qubits seem to be indispensable

Information theory
Andrei Khanov
14:38, 19 November 2020

Philosophy of Science and Technology

Why we are who we are and why - we rarely understand what we are saying to each other. Why, the older we get, the dumber our interlocutors.

I am interested in symbolism, in other words - the structure of information.

One aspect of the practical application of my research is to increase the number of options while maintaining the same levels of reading / transmission of information. This can also be considered as a variant of radical compression of information or - increasing the comfort of its consumption.

The possible compression ratio of information is difficult to estimate accurately. To do this, it is necessary to define the specific task of such "compression" and understand the effectiveness of conventional algorithms. Again, this requires information theory, which, in the public consciousness, does not yet exist.

A new algorithm that fast forwards simulations could bring greater use ability to current and near-term quantum computers, opening the way for applications to run past strict time limits that hamper many quantum calculations. [58] "We will be able to test the output of quantum computers against these calculations," said Krishnamoorthy. "If quantum computers can produce results close to these results, we will know they work." [57] We all learn quantum physics as physics students, but in recent years this field has taken on a whole new life. It's not an esoteric theory anymore, something that only describes tiny effects in extreme forms of matter. It's going to form the basis for a whole new type of technology. So I think that, because physicists have a bit of a leg up in this area, they should go all-in. [56] Scientists from the University of Bath, working with a colleague at the Bulgarian Academy of Sciences, have devised an ingenious method of controlling the vapour by coating the interior of containers with nanoscopic gold particles 300,000 times smaller than a pinhead. [55] Significant technical and financial issues remain towards building a large, fault-tolerant quantum computer and one is unlikely to be built within the coming decade. [54] Chemists at Friedrich Schiller University in Jena (Germany) have now synthesised a molecule that can perform the function of a computing unit in a quantum computer. [53] The research team developed the first optical microchip to generate, manipulate and detect a particular state of light called squeezed vacuum, which is essential for HYPERLINK "https://phys.org/tags/quantum/" quantum computation. [52] Australian scientists have investigated new directions to scale up qubits-utilising the spin-orbit coupling of atom qubits-adding a new suite of tools to the armory. [51] A team of international researchers led by engineers from the National University of Singapore (NUS) have invented a new magnetic device to manipulate digital information 20 times more efficiently and with 10 times more stability than commercial spintronic digital memories. [50]

The most general quantum object that can be shared between two distant parties is a bipartite quantum channel. In general, bipartite channels can produce entangled states, and can be used to simulate quantum operations that are not local. When the input dimensions are trivial, a bipartite channel can be viewed as a bipartite state, and when the output systems are classical the channel can be viewed as a bipartite POVM. While much effort over the last two decades has been devoted to the study of entanglement of bipartite states, very little is known about the entanglement of bipartite channels. In this work, for the first time we rigorously study the entanglement of bipartite channels. We follow a top-down approach, starting from general resource theories of processes, for which we present a new construction of a complete family of monotones, valid in all resource theories where the set of free superchannels is convex. In this setting, we define various general resource-theoretic protocols and resource monotones, which are then applied to the case of entanglement of bipartite channels. We focus in particular on the resource theory of PPT entanglement. Our definition of PPT superchannels is new, as we do not assume that it can be realized by pre- and post-PPT channels. This leads to a greater mathematical simplicity that allows us to express all resource protocols and monotones in terms of semidefinite programs. Along the way, we generalize the negativity measure to bipartite channels, and show that another monotone, the max-logarithmic-negativity, has an operational interpretation as the exact asymptotic entanglement cost of a bipartite channel. Finally, we show that it is not possible to distill entanglement out of bipartite PPT channels under any set of free superchannels that can be used in entanglement theory, leading us in particular to the discovery of bound entangled POVMs.

Many practical problems in all science and technological disciples have been classified as computationally NP hard like combinatorial optimization, prime factorization of large integer, finding the ground state of the Ising Hamiltonian. More specifically, some cryptographic algorithms such as RSA (Rivest–Shamir–Adleman) critically depends on the fact that the terrible difficulty for finding the prime factorization of large integer. A polynomial-time algorithm was invented by Shor for quantum computers. Is there any optical system able to compute such a factoring algorithm? Optical systems are perhaps the most robust and fastest accessible system capable of dealing Shor’s function. In this work, we have developed an optical platform of proof of concept experiment for period finding. We present an experimental and numerical observation, that demonstrate the prime factorization based on Shor’s algorithm using laser light. Scalability is one of the major strength inherent in this DMD (digital micromirror device) based technique. Although, this classical approach cannot compete with the quantum algorithm in terms of efficiency, quantum entanglement can potentially be used aiming at speeding up prime factorization for classical computers.