arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0908.3739cond-mat.mes-hallcond-mat.supr-con
收藏

半填充纳米器件中的跳跃瞬态电流和类SQUID电压

Bouncing transient currents and SQUID-like voltage in nano devices at half filling

Michele Cini, Enrico Perfetto, Chiara Ciccarelli, Gianluca Stefanucci, Stefano Bellucci

摘要:

非对称连接的纳米环在突发激发和恒定电流条件下表现出不同的量子干涉现象。在这里,我们对比了由突然偏置引起的瞬态电流与恒定电流下的磁效应。排斥性杂质可以导致其中一个臂中的电荷积聚和反向电流尖峰。此外,它可以引起从层流到旋涡的转变,也改变了旋涡的手征性。这些器件的磁行为也非常奇特。那些由奇数个原子组成的纳米电路与由偶数个原子组成的纳米电路相比,其行为方式完全不同。具有奇数个站点连接到足够长的对称导线的电路是抗磁性的;即使在没有电子-声子和电子-电子相互作用的情况下,它们也显示由多体对称性引起的半通量周期性。原则上,人们可以在没有超导体的情况下操作一种新的量子干涉装置。由于没有间隙,也没有临界温度,因此可以定性地预测在室温和室温以上的相同行为,尽管电流减小。另一方面,具有偶数位点数的电路是顺磁性的。

英文摘要:

Nanorings asymmetrically connected to wires show different kinds of quantum interference phenomena under sudden excitations and in steady current conditions. Here we contrast the transient current caused by an abrupt bias to the magnetic effects at constant current. A repulsive impurity can cause charge build-up in one of the arms and reverse current spikes. Moreover, it can cause transitions from laminar current flow to vortices, and also change the chirality of the vortex. The magnetic behavior of these devices is also very peculiar. Those nano-circuits which consist of an odd number of atoms behave in a fundamentally different manner compared to those which consist of an even number of atoms. The circuits having an odd number of sites connected to long enough symmetric wires are diamagnetic; they display half-fluxon periodicity induced by many-body symmetry even in the absence of electron-phonon and electron-electron interactions. In principle one can operate a new kind of quantum interference device without superconductors. Since there is no gap and no critical temperature, one predicts qualitatively the same behavior at and above room temperature, although with a reduced current. The circuits with even site numbers, on the other hand, are paramagnetic.

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。

↑