Nonequilibrium dynamics reveal remote Aharonov–Bohm sensitivity in superconductors

Previous time-dependent Ginzburg–Landau simulations demonstrated that Abrikosov vortex dynamics in superconductors can be influenced by Aharonov–Bohm-type curl-less vector potentials even in simply connected geometries, without closed-loop trajectories enclosing magnetic flux [A. M. Gulian et al., Phys. Lett. A 382 (2018) 1058]. The origin of this effect has remained unexplained. Here we investigate further nonequilibrium effects in which the relation between a curl-less vector potential and an evolving quantum state produces observable consequences. During transient nonequilibrium state evolution, collective quantum systems may develop measurable responses to curl-less gauge fields despite a simply connected final equilibrium configuration with no persistent current. Using superconducting condensates, we formulate protocols based on the gauge-invariant coupling between quantum phase and the curl-less vector potential, analyze their dynamics using time-dependent Ginzburg–Landau theory and interpret rapid phase formation within the Kibble–Zurek picture. The predicted transient supercurrents and voltage signals provide a physical interpretation of nonequilibrium sensitivity to curl-less gauge fields and motivate experimental tests.Previous time-dependent Ginzburg–Landau simulations demonstrated that Abrikosov vortex dynamics in superconductors can be influenced by Aharonov–Bohm-type curl-less vector potentials even in simply connected geometries, without closed-loop trajectories enclosing magnetic flux [A. M. Gulian et al., Phys. Lett. A 382 (2018) 1058]. The origin of this effect has remained unexplained. Here we investigate further nonequilibrium effects in which the relation between a curl-less vector potential and an evolving quantum state produces observable consequences. During transient nonequilibrium state evolution, collective quantum systems may develop measurable responses to curl-less gauge fields despite a simply connected final equilibrium configuration with no persistent current. Using superconducting condensates, we formulate protocols based on the gauge-invariant coupling between quantum phase and the curl-less vector potential, analyze their dynamics using time-dependent Ginzburg–Landau theory and interpret rapid phase formation within the Kibble–Zurek picture. The predicted transient supercurrents and voltage signals provide a physical interpretation of nonequilibrium sensitivity to curl-less gauge fields and motivate experimental tests.

Physics Letters AOct 19, 20260 citations

Nonadiabatic dynamics and coherent control of nonequilibrium superconductors

Andreas P. Schnyder

Bulletin of the American Physical SocietyMar 3, 20140 citations

Proposal for testing the electric Aharonov-Bohm effect with superconductors

Thomas C. Bachlechner, Matthew Kleban

The phase of the wave function of charged matter is sensitive to the value of the electric potential, even when the matter never enters any region with nonvanishing electromagnetic fields. Despite its fundamental character, this archetypal electric Aharonov-Bohm effect has evidently never been observed. We propose an experiment to detect the electric potential through its coupling to the superconducting order parameter. A potential difference between two superconductors will induce a relative phase shift that is observable via the DC Josephson effect even when no electromagnetic fields ever act on the superconductors, and even if the potential difference is later reduced to zero. This is a type of electromagnetic memory effect, and would directly demonstrate the physical significance of the electric potential.The phase of the wave function of charged matter is sensitive to the value of the electric potential, even when the matter never enters any region with nonvanishing electromagnetic fields. Despite its fundamental character, this archetypal electric Aharonov-Bohm effect has evidently never been observed. We propose an experiment to detect the electric potential through its coupling to the superconducting order parameter. A potential difference between two superconductors will induce a relative phase shift that is observable via the DC Josephson effect even when no electromagnetic fields ever act on the superconductors, and even if the potential difference is later reduced to zero. This is a type of electromagnetic memory effect, and would directly demonstrate the physical significance of the electric potential.

arXiv:1909.11668Physical review. B./Physical review. BMay 4, 20205 citations

Intrinsic coherence dynamics and phase localization in Aharonov-Bohm Interferometers

Matisse Wei-Yuan Tu, Wei-Min Zhang, Jinshuang Jin

The nonequilibrium real-time dynamics of electron coherence is explored in the quantum transport through the double-dot Aharonov-Bohm interferometers. We solve the exact master equation to find the exact quantum state of the device, from which the changes of the electron coherence through the magnetic flux in the nonequilibrium transport processes is obtained explicitly. We find that the relative phase between the two charge states of the double dot localizes to $\fracπ{2}$ or $-\fracπ{2}$ for all different magnetic flux. This nontrivial phase localization process can be manifested in the measurable occupation numbers.The nonequilibrium real-time dynamics of electron coherence is explored in the quantum transport through the double-dot Aharonov-Bohm interferometers. We solve the exact master equation to find the exact quantum state of the device, from which the changes of the electron coherence through the magnetic flux in the nonequilibrium transport processes is obtained explicitly. We find that the relative phase between the two charge states of the double dot localizes to $\fracπ{2}$ or $-\fracπ{2}$ for all different magnetic flux. This nontrivial phase localization process can be manifested in the measurable occupation numbers.

arXiv:1010.1977Oct 11, 20100 citations

\fracπ{2}

-\fracπ{2}

for all different magnetic flux. This nontrivial phase localization process can be manifested in the measurable occupation numbers.