ABSTRACT Strongly interacting pairs of atoms in a lattice can form tighly bound dimers [1]. In tu... more ABSTRACT Strongly interacting pairs of atoms in a lattice can form tighly bound dimers [1]. In turn, such dimers interact with each other via attractive nearest-neighbor interaction mediated by virtual (second order) hopping [2]. In the case of bosons, the dimers can form a stable, incompressible cluster corresponding to a finite-size Mott insulator. Unpaired bosons in such a cluster represent highly mobile defects. We study the dynamics of these defects in 1D clusters using analytical techniques and t-DMRG simulations. We discuss how the quasi-thermalization of the defects mediated by their collisions, followed by evaporation through the boundary of the cluster, can purify the Mott insulator.
We study resonant optical excitations of spatially frozen atoms in 1D trapping potentials and lat... more We study resonant optical excitations of spatially frozen atoms in 1D trapping potentials and lattices to strongly-interacting Rydberg states. In the steady-state of strong uniform driving, correlations of Rydberg excitation probabilities exhibit exponentially decaying spatial oscillations with the period approaching one collective excitation per Rydberg blockade distance (superatom). For few atoms per blockade distance, the system is well described by a rate equation model with hard sphere superatoms. For higher densities approaching a continuous limit, we find via numerical simulations that the superatoms develop soft boundaries. For the case of an additional lattice we derive an effective master equation with non-local damping. We give analytic expressions for the many-body steady state and the correlation length of the Rydberg quasi-crystal or antiferromagnetic order and discuss conditions when it can approach infinity.
Proceedings of SPIE - The International Society for Optical Engineering, 2005
ABSTRACT A scalable multatom entangled system, capable of high-performance quantum computations, ... more ABSTRACT A scalable multatom entangled system, capable of high-performance quantum computations, can be realized by resonant dipole-dipole interacting dopants in a solid state host. In one realization, the qubits are represented by ground and subradiant states of effective dimers formed by pairs of closely spaced two-level systems (TLS). Such qubits are highly robust against radiative decay. The two-qubit entanglement in this scheme relies on coherent excitation exchange between the dimers by external laser fields. This scheme is challenging because of the nanosize control and addressability it requires. Another realization involves dipole-dipole interacting TLS whose resonance frequency lies in a photonic band gap of a dielectric photonic crystal. A sequence of abrupt changes of the resonance frequency can produce controlled entanglement (logic gates) with improved protection from radiation decay and decoherence.
We consider scattering of a single particle from an interaction-bound pair of particles in the on... more We consider scattering of a single particle from an interaction-bound pair of particles in the one-dimensional Bose-Hubbard model. We show that the transmission probability of the single particle is always significantly smaller than unity. This invalidates the main result of ...
We examine two-photon lasing in competition with the one-photon lasing into a second mode near re... more We examine two-photon lasing in competition with the one-photon lasing into a second mode near resonance with a transition to an intermediate state. The model assumes pumping to the upper state of the two-photon transition. After a derivation of the relevant master equation for the atomic system, we consider the Maxwell-Bloch equation on the basis of which we study the steady state and the time-dependent dynamical behavior of the system. We show that two-photon lasing can be sustained in coexistence with one-photon lasing after the latter is saturated. The results are illustrated with an application to a specific atomic system (potassium) as an amplifying medium.
ABSTRACT Strongly interacting pairs of atoms in a lattice can form tighly bound dimers [1]. In tu... more ABSTRACT Strongly interacting pairs of atoms in a lattice can form tighly bound dimers [1]. In turn, such dimers interact with each other via attractive nearest-neighbor interaction mediated by virtual (second order) hopping [2]. In the case of bosons, the dimers can form a stable, incompressible cluster corresponding to a finite-size Mott insulator. Unpaired bosons in such a cluster represent highly mobile defects. We study the dynamics of these defects in 1D clusters using analytical techniques and t-DMRG simulations. We discuss how the quasi-thermalization of the defects mediated by their collisions, followed by evaporation through the boundary of the cluster, can purify the Mott insulator.
We study resonant optical excitations of spatially frozen atoms in 1D trapping potentials and lat... more We study resonant optical excitations of spatially frozen atoms in 1D trapping potentials and lattices to strongly-interacting Rydberg states. In the steady-state of strong uniform driving, correlations of Rydberg excitation probabilities exhibit exponentially decaying spatial oscillations with the period approaching one collective excitation per Rydberg blockade distance (superatom). For few atoms per blockade distance, the system is well described by a rate equation model with hard sphere superatoms. For higher densities approaching a continuous limit, we find via numerical simulations that the superatoms develop soft boundaries. For the case of an additional lattice we derive an effective master equation with non-local damping. We give analytic expressions for the many-body steady state and the correlation length of the Rydberg quasi-crystal or antiferromagnetic order and discuss conditions when it can approach infinity.
Proceedings of SPIE - The International Society for Optical Engineering, 2005
ABSTRACT A scalable multatom entangled system, capable of high-performance quantum computations, ... more ABSTRACT A scalable multatom entangled system, capable of high-performance quantum computations, can be realized by resonant dipole-dipole interacting dopants in a solid state host. In one realization, the qubits are represented by ground and subradiant states of effective dimers formed by pairs of closely spaced two-level systems (TLS). Such qubits are highly robust against radiative decay. The two-qubit entanglement in this scheme relies on coherent excitation exchange between the dimers by external laser fields. This scheme is challenging because of the nanosize control and addressability it requires. Another realization involves dipole-dipole interacting TLS whose resonance frequency lies in a photonic band gap of a dielectric photonic crystal. A sequence of abrupt changes of the resonance frequency can produce controlled entanglement (logic gates) with improved protection from radiation decay and decoherence.
We consider scattering of a single particle from an interaction-bound pair of particles in the on... more We consider scattering of a single particle from an interaction-bound pair of particles in the one-dimensional Bose-Hubbard model. We show that the transmission probability of the single particle is always significantly smaller than unity. This invalidates the main result of ...
We examine two-photon lasing in competition with the one-photon lasing into a second mode near re... more We examine two-photon lasing in competition with the one-photon lasing into a second mode near resonance with a transition to an intermediate state. The model assumes pumping to the upper state of the two-photon transition. After a derivation of the relevant master equation for the atomic system, we consider the Maxwell-Bloch equation on the basis of which we study the steady state and the time-dependent dynamical behavior of the system. We show that two-photon lasing can be sustained in coexistence with one-photon lasing after the latter is saturated. The results are illustrated with an application to a specific atomic system (potassium) as an amplifying medium.
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Papers by David Petrosyan