Helical gaps in interacting Rashba wires at low electron densities

Rashba spin-orbit coupling and a magnetic field perpendicular to the Rashba axis have been predicted to open a partial gap ("helical gap") in the energy spectrum of noninteracting or weakly interacting one-dimensional quantum wires. By comparing kinetic energy and Coulomb energy we show th...

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Bibliographic Details
Published in:arXiv.org 2016-09
Main Authors: Schmidt, Thomas L, Pedder, Christopher J
Format: Article
Language:English
Subjects:
Dependence
Electron density
Electron spin
Electrons
Energy spectra
Kinetic energy
Magnetic fields
Plasma
Quantum wires
Resistance
Spin-orbit interactions
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Summary:Rashba spin-orbit coupling and a magnetic field perpendicular to the Rashba axis have been predicted to open a partial gap ("helical gap") in the energy spectrum of noninteracting or weakly interacting one-dimensional quantum wires. By comparing kinetic energy and Coulomb energy we show that this gap opening typically occurs at low electron densities where the Coulomb energy dominates. To address this strongly correlated limit, we investigate Rashba wires using Wigner crystal theory. We find that the helical gap exists even in the limit of strong interactions but its dependence on electron density differs significantly from the weakly interacting case. In particular, we find that the critical magnetic field for opening the gap becomes an oscillatory function of electron density. This changes strongly the expected signature of the helical gap in conductance measurements.
ISSN:2331-8422
DOI:10.48550/arxiv.1604.07720