We analyze a ballistic electron transport through a corrugated (rippled) graphene system with a c... more We analyze a ballistic electron transport through a corrugated (rippled) graphene system with a curvature-induced spin–orbit interaction. The corrugated system is connected from both sides to two flat graphene sheets. The rippled structure unit is modeled by upward and downward curved surfaces. The cooperative effect of N units connected together (the superlattice) on the transmission of electrons that incident at the arbitrary angles on the superlattice is considered. The set of optimal angles and corresponding numbers of N units that yield the robust spin inverter phenomenon are found.
New model is suggested, where the Casimir mechanism is the source of masses and conformal symmetr... more New model is suggested, where the Casimir mechanism is the source of masses and conformal symmetry breaking at the Planck epoch in the beginning of the Universe. The mechanism is the Casimir energy and associated condensate, which are resulted from the vacuum postulate and normal ordering of the conformal invariant Hamiltonian with respect to the quantum elementary field operators. It is shown that the Casimir top-quark condensate specifies the value of the Higgs particle mass without involving the Higgs tachyon mass, which are put equal to zero. The Casimir mechanism yields another value of the coupling constant for the self-interaction of scalar field than the standard model does.
We show that the axial symmetry of the Bychkov–Rashba interaction can be exploited to produce ele... more We show that the axial symmetry of the Bychkov–Rashba interaction can be exploited to produce electron spin-flip in a circular quantum dot, without lifting the time reversal symmetry. In order to elucidate this effect, we consider ballistic electron transmission through a two-dimensional circular billiard coupled to two one-dimensional electrodes. Using the tight-binding approximation, we derive the scattering matrix and the effective Hamiltonian for the considered system. Within this approach, we found the conditions for the optimal realization of this effect in the transport properties of the quantum dot. Numerical analysis of the system, extended to the case of two-dimensional electrodes, confirms our findings. The relatively strong quantization of the quantum dot can make this effect robust against the temperature effects.
We analyse the evolution of a weak probe optical field propagation through a five-level atomic me... more We analyse the evolution of a weak probe optical field propagation through a five-level atomic medium cyclically driven by two strong optical and microwave fields. It is shown that the competition between the electromagnetically induced transparency and the Autler-Townes effect can be controlled by altering the relative phase of the coupling fields in the presence of the atomic dephasing reservoir.
Journal of Physics-condensed Matter - J PHYS-CONDENS MATTER, 1999
Crossings between spin-singlet and spin-triplet lowest states are analysed within the model of a ... more Crossings between spin-singlet and spin-triplet lowest states are analysed within the model of a two-electron quantum dot in a perpendicular magnetic field. The explicit expressions in terms of the magnetic field, the magnetic quantum number m of the state and the dimensionless dot size for these crossings are found.
We analyse the interplay between Dresselhaus, Bychkov-Rashba, and Zeeman interactions in a two-di... more We analyse the interplay between Dresselhaus, Bychkov-Rashba, and Zeeman interactions in a two-dimensional semiconductor quantum system under the action of a magnetic field. When a vertical magnetic field is considered, we predict that the interplay results in an effective cyclotron frequency that depends on a spin-dependent contribution. For in-plane magnetic fields, we found that the interplay induces an anisotropic effective
Physical Review B Condensed Matter and Materials Physics, May 1, 2009
We show that spin precession in a semiconductor quantum wire, caused by the Rashba and the Dresse... more We show that spin precession in a semiconductor quantum wire, caused by the Rashba and the Dresselhaus interactions (both of arbitrary strengths), can be suppressed by dint of an in-plane magnetic field. Using a condition of the translational invariance in the longitudinal coordinate, we found another type of symmetry, which arises at a particular set of intensity and orientation of the magnetic field and explains this suppression. Based on our findings, we propose a transport experiment to measure the strengths of the Rashba and the Dresselhaus interactions.
We show that spin-flip rotation in a semiconductor quantum wire, caused by the Rashba and the Dre... more We show that spin-flip rotation in a semiconductor quantum wire, caused by the Rashba and the Dresselhaus interactions (both of arbitrary strengths), can be suppressed by dint of an in-plane magnetic field. We found a new type of symmetry, which arises at a particular set of intensity and orientation of the magnetic field and explains this suppression. Based on our findings, we propose a transport experiment to measure the strengths of the Rashba and the Dresselhaus interactions.
Physical Review B Condensed Matter and Materials Physics, Aug 1, 2002
We analyze the transport phenomena of two-dimensional quantum billiards with convex boundary of d... more We analyze the transport phenomena of two-dimensional quantum billiards with convex boundary of different shape. The quantum mechanical analysis is performed by means of the poles of the S matrix while the classical analysis is based on the motion of a free particle inside the cavity along trajectories with a different number of bounces at the boundary. The value of the conductance depends on the manner in which the leads are attached to the cavity. The Fourier transform of the transmission amplitudes is compared with the length of the classical paths. There is good agreement between classical and quantum mechanical results when the conductance is achieved mainly by special short-lived states such as whispering gallery modes and bouncing ball modes. In these cases, also the localization of the wave functions agrees with the picture of the classical paths. The S matrix is calculated classically and compared with the transmission coefficients of the quantum mechanical calculations for five modes in each lead. The number of modes coupled to the special states is effectively reduced.
We analyze a ballistic electron transport through a corrugated (rippled) graphene system with a c... more We analyze a ballistic electron transport through a corrugated (rippled) graphene system with a curvature-induced spin–orbit interaction. The corrugated system is connected from both sides to two flat graphene sheets. The rippled structure unit is modeled by upward and downward curved surfaces. The cooperative effect of N units connected together (the superlattice) on the transmission of electrons that incident at the arbitrary angles on the superlattice is considered. The set of optimal angles and corresponding numbers of N units that yield the robust spin inverter phenomenon are found.
New model is suggested, where the Casimir mechanism is the source of masses and conformal symmetr... more New model is suggested, where the Casimir mechanism is the source of masses and conformal symmetry breaking at the Planck epoch in the beginning of the Universe. The mechanism is the Casimir energy and associated condensate, which are resulted from the vacuum postulate and normal ordering of the conformal invariant Hamiltonian with respect to the quantum elementary field operators. It is shown that the Casimir top-quark condensate specifies the value of the Higgs particle mass without involving the Higgs tachyon mass, which are put equal to zero. The Casimir mechanism yields another value of the coupling constant for the self-interaction of scalar field than the standard model does.
We show that the axial symmetry of the Bychkov–Rashba interaction can be exploited to produce ele... more We show that the axial symmetry of the Bychkov–Rashba interaction can be exploited to produce electron spin-flip in a circular quantum dot, without lifting the time reversal symmetry. In order to elucidate this effect, we consider ballistic electron transmission through a two-dimensional circular billiard coupled to two one-dimensional electrodes. Using the tight-binding approximation, we derive the scattering matrix and the effective Hamiltonian for the considered system. Within this approach, we found the conditions for the optimal realization of this effect in the transport properties of the quantum dot. Numerical analysis of the system, extended to the case of two-dimensional electrodes, confirms our findings. The relatively strong quantization of the quantum dot can make this effect robust against the temperature effects.
We analyse the evolution of a weak probe optical field propagation through a five-level atomic me... more We analyse the evolution of a weak probe optical field propagation through a five-level atomic medium cyclically driven by two strong optical and microwave fields. It is shown that the competition between the electromagnetically induced transparency and the Autler-Townes effect can be controlled by altering the relative phase of the coupling fields in the presence of the atomic dephasing reservoir.
Journal of Physics-condensed Matter - J PHYS-CONDENS MATTER, 1999
Crossings between spin-singlet and spin-triplet lowest states are analysed within the model of a ... more Crossings between spin-singlet and spin-triplet lowest states are analysed within the model of a two-electron quantum dot in a perpendicular magnetic field. The explicit expressions in terms of the magnetic field, the magnetic quantum number m of the state and the dimensionless dot size for these crossings are found.
We analyse the interplay between Dresselhaus, Bychkov-Rashba, and Zeeman interactions in a two-di... more We analyse the interplay between Dresselhaus, Bychkov-Rashba, and Zeeman interactions in a two-dimensional semiconductor quantum system under the action of a magnetic field. When a vertical magnetic field is considered, we predict that the interplay results in an effective cyclotron frequency that depends on a spin-dependent contribution. For in-plane magnetic fields, we found that the interplay induces an anisotropic effective
Physical Review B Condensed Matter and Materials Physics, May 1, 2009
We show that spin precession in a semiconductor quantum wire, caused by the Rashba and the Dresse... more We show that spin precession in a semiconductor quantum wire, caused by the Rashba and the Dresselhaus interactions (both of arbitrary strengths), can be suppressed by dint of an in-plane magnetic field. Using a condition of the translational invariance in the longitudinal coordinate, we found another type of symmetry, which arises at a particular set of intensity and orientation of the magnetic field and explains this suppression. Based on our findings, we propose a transport experiment to measure the strengths of the Rashba and the Dresselhaus interactions.
We show that spin-flip rotation in a semiconductor quantum wire, caused by the Rashba and the Dre... more We show that spin-flip rotation in a semiconductor quantum wire, caused by the Rashba and the Dresselhaus interactions (both of arbitrary strengths), can be suppressed by dint of an in-plane magnetic field. We found a new type of symmetry, which arises at a particular set of intensity and orientation of the magnetic field and explains this suppression. Based on our findings, we propose a transport experiment to measure the strengths of the Rashba and the Dresselhaus interactions.
Physical Review B Condensed Matter and Materials Physics, Aug 1, 2002
We analyze the transport phenomena of two-dimensional quantum billiards with convex boundary of d... more We analyze the transport phenomena of two-dimensional quantum billiards with convex boundary of different shape. The quantum mechanical analysis is performed by means of the poles of the S matrix while the classical analysis is based on the motion of a free particle inside the cavity along trajectories with a different number of bounces at the boundary. The value of the conductance depends on the manner in which the leads are attached to the cavity. The Fourier transform of the transmission amplitudes is compared with the length of the classical paths. There is good agreement between classical and quantum mechanical results when the conductance is achieved mainly by special short-lived states such as whispering gallery modes and bouncing ball modes. In these cases, also the localization of the wave functions agrees with the picture of the classical paths. The S matrix is calculated classically and compared with the transmission coefficients of the quantum mechanical calculations for five modes in each lead. The number of modes coupled to the special states is effectively reduced.
Uploads
Papers by Rashid Nazmitdinov