Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1803.08246 · New Journal of Physics

Time-resolved quantum spin transport through an Aharonov–Casher ring

Can Li, Yaojin Li, Dongxing Yu, Chenglong Jia

Published Sep 7, 2018• 0 citations
arXivHTMLPDF

Abstract

After obtaining an exact analytical time-varying solution for the Aharonov–Casher conducting ring embedded in a textured static/dynamic electric field, we investigate the spin-resolved quantum transport in the structure. It is shown that the interference patterns are governed by not only the Aharonov–Casher geometry phase but also the instantaneous phase difference of spin precession through different traveling paths. This dynamic phase is determined by the strength of the applied electric field and can have substantial effects on the charge/spin conductances, especially in the weak field regime as the period of spin precession comparable to that of the orbital motion. Our studies suggest that a low-frequency normal electric field with moderate strength possesses more degrees of freedom for manipulating the spin interference of incident electrons.

DOI
10.1088/1367-2630/aadfa4

Related papers

Quantum transport by nonadiabatic Aharonov-Casher phase in mesoscopic rings

Taeseung Choi, Sam Young Cho, Chang‐Mo Ryu +1 more

We have studied the quantum transport by nonadiabatic Aharonov-Casher phase in mesoscopic rings embedded in textured electric fields. The quantum transport of the electron is examined based on a one-dimensional quantum waveguide theory. Periodic behaviors of the transmission probability are found in the domain when the quantum phase approaches an adiabatic limit, whereas anomalous quantum transport is shown in the nonadiabatic domain. The difference between the angle of the spin and that of the electric field is found to determine the detailed characteristics of the nonadiabatic quantum phase and transport. The destructive pattern of the transmission probability is found to occur in accordance with the abrupt change of the persistent current in an isolated ring.

Physical review. B, Condensed matter•Aug 15, 1997•45 citations

Persistent currents from Berry’s phase in mesoscopic systems

Daniel Loss, Paul M. Goldbart

The quantum orbital motion of electrons in mesoscopic normal-metal rings threaded by a magnetic flux produces striking interference phenomena such as persistent currents due to the Aharonov-Bohm effect. Similarly, when a quantum spin adiabatically follows a magnetic field that rotates slowly in time, the phase of its state vector acquires an additional contribution known as the Berry phase. We explore the combination of these two quantum phenomena by examining the interplay between orbital and spin degrees of freedom for a charged spin-1/2 particle moving in a mesoscopic ring embedded in a classical, static inhomogeneous magnetic field, i.e, a texture. As a consequence of its orbital motion through the texture, the spin experiences, via the Zeeman interaction, a varying magnetic field. This results in a Berry---or geometric---phase, leading to persistent (i.e., equilibrium) currents of charge and spin. These mesoscopic phenomena are related to (but should be distinguished from) the conventional persistent currents that result from magnetic flux through a ring. We develop a path-integral approach to decouple the orbital and spin motion and, by using an adiabatic approximation, we compute the equilibrium expectation values of the persistent charge and spin currents and the magnetization. We find that the persistent currents depend on the texture in a striking manner through a geometric phase (related to a surface area characterizing the texture) and a geometric vector (related to the projections of this area). In the special case of a cylindrically symmetric texture we use a spectrum obtained by Kuratsuji and Iida to obtain exact results that confirm, independently, the validity of the path-integral approach in the adiabatic limit. We discuss the connection between the geometric vector and quantum-mechanical correlations, and examine quantum fluctuations and the zero-point energy.

Physical review. B, Condensed matter•Jun 15, 1992•193 citations

Directional Dependence of Spin Currents Induced by Aharonov–Casher Phase

Taeseung Choi, Chang‐Mo Ryu, A. M. Jayannavar

We have calculated the persistent spin current of an open ring induced by the Aharonov–Casher phase. For unpolarized electrons there exist no persistent charge currents, but persistent spin currents. We show that, in general, the magnitude of the persistent spin current in a ring depends on the direction of the direct current flow from one reservoir to another. The persistent spin current is modulated by the cosine function of the spin precession angle. The nonadiabatic Aharonov–Casher phase gives anomalous behaviors. The Aharonov–Anandan phase is determined by the solid angle of spin precession. When the nonadiabatic Aharonov–Anandan phase approaches a constant value with the increase of the electric field, the periodic behavior of the spin persistent current occurs in an adiabatic limit. In this limit the periodic behavior of the persistent spin current could be understood by the effective spin-dependent Aharonov–Bohm flux.

arXiv:cond-mat/9802037•International Journal of Modern Physics B•Aug 10, 1998•15 citations

Electron spin transport through an Aharonov–Bohm ring—a spin switch

Chenglong Jia, Shun-Jin Wang, Hong‐Gang Luo +1 more

Electron spin transport through an Aharonov–Bohm ring driven by time-dependent inhomogeneous magnetic fields is treated. The system possesses an su (2) l × su (2) s dynamical symmetry in both orbital angular momentum space and spin space, and is thus proved to be integrable according to algebraic dynamics. Based on the analytical solutions, the relevant physical quantities such as electric current, spin current, magnetization and conductance are calculated. It is found that for a magnetic field with π/2 twist angle, the direction of spin-polarization will be reversed at zero magnetic flux. In the resonant rotating magnetic field, the spin transmission is oscillating with time t , and can reach unity, so that a complete spin flip can also be induced. The results obtained may be of practical significance for the design of nano-electromagnetic spin devices, such as a spin switch, in a controllable way.

Journal of Physics Condensed Matter•Mar 12, 2004•3 citations

Quantum Interference of Electrons in a Ring: Tuning of the Geometrical Phase

Rosario Capozza, Domenico Giuliano, Procolo Lucignano +1 more

We calculate the oscillations of the dc conductance across a mesoscopic ring, simultaneously tuned by applied magnetic and electric fields orthogonal to the ring. The oscillations depend on the Aharonov-Bohm flux and of the spin-orbit coupling. They result from mixing of the dynamical phase, including the Zeeman spin splitting, and of geometric phases. By changing the applied fields, the geometric phase contribution to the conductance oscillations can be tuned from the adiabatic (Berry) to the nonadiabatic (Ahronov-Anandan) regime. To model a realistic device, we also include nonzero backscattering at the connection between ring and contacts, and a random phase for electron wave function, accounting for dephasing effects.

arXiv:cond-mat/0505273•Physical Review Letters•Nov 23, 2005•27 citations

Aharonov-Casher effect in the Heisenberg spin chain with many impurities

Andrei A. Zvyagin, P. Schlottmann

The Aharonov-Casher effect is a quantum interference arising in mesoscopic rings involving particles with magnetic moments. The wave function acquires a phase due to an electric-field flux F enclosed by the ring and gives rise to flux-dependent oscillations in persistent spin currents. In the ground state of the spin-1/2 Heisenberg chain the period and amplitude of the oscillations are associated with the properties of the Fermi surface of the elementary excitations of the spin chain (spinons). We consider an antiferromagnetic spin-1/2 Heisenberg ring with a concentration x of impurity spins S. The calculations are performed within the framework of Bethe's ansatz. Due to the finite concentration of impurities the ground state consists of two (rather than one) Dirac seas, corresponding to spinons and 2S strings of rapidities. The persistent spin current reveals two periods of oscillation associated with the properties of the two Fermi seas. The interference pattern as a function of F is discussed for several external magnetic fields.

Physical review. B, Condensed matter•Sep 1, 1995•48 citations
After obtaining an exact analytical time-varying solution for the Aharonov–Casher conducting ring embedded in a textured static/dynamic electric field, we investigate the spin-resolved quantum transport in the structure. It is shown that the interference patterns are governed by not only the Aharonov–Casher geometry phase but also the instantaneous phase difference of spin precession through different traveling paths. This dynamic phase is determined by the strength of the applied electric field and can have substantial effects on the charge/spin conductances, especially in the weak field regime as the period of spin precession comparable to that of the orbital motion. Our studies suggest that a low-frequency normal electric field with moderate strength possesses more degrees of freedom for manipulating the spin interference of incident electrons.
We have studied the quantum transport by nonadiabatic Aharonov-Casher phase in mesoscopic rings embedded in textured electric fields. The quantum transport of the electron is examined based on a one-dimensional quantum waveguide theory. Periodic behaviors of the transmission probability are found in the domain when the quantum phase approaches an adiabatic limit, whereas anomalous quantum transport is shown in the nonadiabatic domain. The difference between the angle of the spin and that of the electric field is found to determine the detailed characteristics of the nonadiabatic quantum phase and transport. The destructive pattern of the transmission probability is found to occur in accordance with the abrupt change of the persistent current in an isolated ring.
The quantum orbital motion of electrons in mesoscopic normal-metal rings threaded by a magnetic flux produces striking interference phenomena such as persistent currents due to the Aharonov-Bohm effect. Similarly, when a quantum spin adiabatically follows a magnetic field that rotates slowly in time, the phase of its state vector acquires an additional contribution known as the Berry phase. We explore the combination of these two quantum phenomena by examining the interplay between orbital and spin degrees of freedom for a charged spin-1/2 particle moving in a mesoscopic ring embedded in a classical, static inhomogeneous magnetic field, i.e, a texture. As a consequence of its orbital motion through the texture, the spin experiences, via the Zeeman interaction, a varying magnetic field. This results in a Berry---or geometric---phase, leading to persistent (i.e., equilibrium) currents of charge and spin. These mesoscopic phenomena are related to (but should be distinguished from) the conventional persistent currents that result from magnetic flux through a ring. We develop a path-integral approach to decouple the orbital and spin motion and, by using an adiabatic approximation, we compute the equilibrium expectation values of the persistent charge and spin currents and the magnetization. We find that the persistent currents depend on the texture in a striking manner through a geometric phase (related to a surface area characterizing the texture) and a geometric vector (related to the projections of this area). In the special case of a cylindrically symmetric texture we use a spectrum obtained by Kuratsuji and Iida to obtain exact results that confirm, independently, the validity of the path-integral approach in the adiabatic limit. We discuss the connection between the geometric vector and quantum-mechanical correlations, and examine quantum fluctuations and the zero-point energy.
We have calculated the persistent spin current of an open ring induced by the Aharonov–Casher phase. For unpolarized electrons there exist no persistent charge currents, but persistent spin currents. We show that, in general, the magnitude of the persistent spin current in a ring depends on the direction of the direct current flow from one reservoir to another. The persistent spin current is modulated by the cosine function of the spin precession angle. The nonadiabatic Aharonov–Casher phase gives anomalous behaviors. The Aharonov–Anandan phase is determined by the solid angle of spin precession. When the nonadiabatic Aharonov–Anandan phase approaches a constant value with the increase of the electric field, the periodic behavior of the spin persistent current occurs in an adiabatic limit. In this limit the periodic behavior of the persistent spin current could be understood by the effective spin-dependent Aharonov–Bohm flux.
Electron spin transport through an Aharonov–Bohm ring driven by time-dependent inhomogeneous magnetic fields is treated. The system possesses an su (2) l × su (2) s dynamical symmetry in both orbital angular momentum space and spin space, and is thus proved to be integrable according to algebraic dynamics. Based on the analytical solutions, the relevant physical quantities such as electric current, spin current, magnetization and conductance are calculated. It is found that for a magnetic field with π/2 twist angle, the direction of spin-polarization will be reversed at zero magnetic flux. In the resonant rotating magnetic field, the spin transmission is oscillating with time t , and can reach unity, so that a complete spin flip can also be induced. The results obtained may be of practical significance for the design of nano-electromagnetic spin devices, such as a spin switch, in a controllable way.
We calculate the oscillations of the dc conductance across a mesoscopic ring, simultaneously tuned by applied magnetic and electric fields orthogonal to the ring. The oscillations depend on the Aharonov-Bohm flux and of the spin-orbit coupling. They result from mixing of the dynamical phase, including the Zeeman spin splitting, and of geometric phases. By changing the applied fields, the geometric phase contribution to the conductance oscillations can be tuned from the adiabatic (Berry) to the nonadiabatic (Ahronov-Anandan) regime. To model a realistic device, we also include nonzero backscattering at the connection between ring and contacts, and a random phase for electron wave function, accounting for dephasing effects.
The Aharonov-Casher effect is a quantum interference arising in mesoscopic rings involving particles with magnetic moments. The wave function acquires a phase due to an electric-field flux F enclosed by the ring and gives rise to flux-dependent oscillations in persistent spin currents. In the ground state of the spin-1/2 Heisenberg chain the period and amplitude of the oscillations are associated with the properties of the Fermi surface of the elementary excitations of the spin chain (spinons). We consider an antiferromagnetic spin-1/2 Heisenberg ring with a concentration x of impurity spins S. The calculations are performed within the framework of Bethe's ansatz. Due to the finite concentration of impurities the ground state consists of two (rather than one) Dirac seas, corresponding to spinons and 2S strings of rapidities. The persistent spin current reveals two periods of oscillation associated with the properties of the two Fermi seas. The interference pattern as a function of F is discussed for several external magnetic fields.