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arXiv 1604.07720cond-mat.mes-hallcond-mat.str-el
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低电子密度下相互作用Rashba线的螺旋带隙

Helical gaps in interacting Rashba wires at low electron densities

Thomas L. Schmidt, Christopher J. Pedder

摘要:

Rashba自旋轨道耦合和垂直于Rashba轴的磁场已经被预测在非相互作用或弱相互作用的一维量子线的能谱中打开部分能隙(“螺旋能隙”)。通过比较动能和库仑能,我们表明,这种间隙开放通常发生在低电子密度的库仑能占主导地位。为了解决这个强相关的限制,我们调查Rashba线使用维格纳晶体理论。我们发现即使在强相互作用的极限下也存在螺旋能隙,但它对电子密度的依赖性与弱相互作用的情况有很大的不同。特别地,我们发现打开间隙的临界磁场成为电子密度的振荡函数。这强烈地改变了电导测量中螺旋间隙的预期特征。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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