Seeking Maxwell's Demon in a non-reciprocal quantum ring.

Area of Science:

• Quantum physics
• Condensed matter physics
• Nanotechnology

Background:

• The Aharonov-Bohm effect is a fundamental quantum phenomenon observed in electron transport through rings.
• Rashba spin-orbit interaction (SOI) significantly influences electron behavior in low-dimensional systems.
• Controlling electron spin states is crucial for quantum information processing.

Purpose of the Study:

• To investigate the electronic properties of a non-reciprocal quantum ring with asymmetric Rashba SOI.
• To explore the absence of Aharonov-Bohm oscillations in such a system.
• To demonstrate nanoscale spin sorting analogous to Maxwell's demon.

Main Methods:

• Theoretical modeling of electron transport in a quantum ring with one arm exhibiting Rashba SOI.
• Analysis of electron behavior under varying magnetic fields.
• Investigation of kinetic energy and spin temperature distributions.

Main Results:

• Aharonov-Bohm oscillations are completely suppressed due to magnetic-field-dependent electron localization in different ring arms.
• Significant differences in average kinetic energy are observed between the two arms.
• Distinct "spin temperatures" arise in each arm, indicating spin polarization.

Conclusions:

• The non-reciprocal quantum ring exhibits unique electronic properties, including the absence of Aharonov-Bohm oscillations.
• The system demonstrates nanoscale spin sorting by manipulating magnetic fields, akin to Maxwell's demon.
• This work highlights the potential of asymmetric SOI for novel quantum devices and information manipulation.