Chiral and nonchiral edge states in quantum Hall systems with charge density modulation

We consider a system of weakly coupled wires with quantum Hall effect (QHE) and in the presence of a spatially periodic modulation of the chemical potential along the wire, equivalent to a charge density wave (CDW). We investigate the competition between the two effects which both open a gap. We show that by changing the ratio between the amplitudes of the CDW modulation and the tunneling between wires, one can switch between nontopological CDW-dominated phase to topological QHE-dominated phase. Both phases host edge states of chiral and nonchiral nature robust to on-site disorder. However, only in the topological phase, the edge states are immune to disorder in the phase shifts of the CDWs. We provide analytical solutions for filling factor nu = 1 and study numerically effects of disorder as well as present numerical results for higher filling factors

Nanodevice for High Precision Readout of Electron Spin

In this paper we propose and simulate operation of a nanodevice, which enables the electron spin accumulation and very precise read-out of its final value. We exploit the dependence of the electron trajectory on its spin state due to the spin-orbit coupling in order to distinguish between different spin orientations