Hall effect between parallel quantum wires

We study theoretically the parallel quantum wires of the experiment by Auslaender et al. [Science 308, 88 (2005)] at low electron density. It is shown that a Hall effect as observed in two- or three-dimensional electron systems develops as one of the two wires enters the spin-incoherent regime of small spin bandwidth. This together with magnetic field dependent tunneling exponents clearly identifies spin-incoherence in such experiments and it serves to distinguish it from disorder effects.Comment: 5 pages, 2 figures, missing summation added to Eq. (6), more thorough discussion of the experimental signature

Pseudospin entanglement and Bell test in graphene

We propose a way of producing and detecting pseudospin entanglement between electrons and holes in graphene. Electron-hole pairs are produced by a fluctuating potential and their entanglement is demonstrated by a current correlation measurement. The chirality of electrons in graphene facilitates a well-controlled Bell test with (pseudo-)spin projection angles defined in real space.Comment: 9 pages, 2 figures; v2 with slightly modified abstract and introductio

Nonequilibrium effective vector potential due to pseudospin exchange in graphene

We show that exchange interactions in two-dimensional electron gases out of equilibrium can generate a fictitious vector potential with intriguing signatures in interference and Hall measurements. Detailed predictions are made for graphene, where the effect is enhanced by pseudospin exchange.Comment: 4 pages, 2 figure

Multiple crossovers in interacting quantum wires

We study tunneling of electrons into and between interacting wires in the spin-incoherent regime subject to a magnetic field. The tunneling currents follow power laws of the applied voltage with exponents that depend on whether the electron spins at the relevant length scales are polarized or disordered. The crossover length (or energy) scale is exponential in the applied field. In a finite size wire multiple crossovers can occur.Comment: 7 pages, 2 figure

Full counting statistics of a general quantum mechanical variable

We present here a quantum mechanical framework for defining the statistics of measurements of time integrals of A(t), A(t) being a quantum mechanical variable. This is a generalization of the so-called full counting statistics proposed earlier for DC electric currents. We develop an influence functional formalism that allows us to study the quantum system along with the measuring device thus fully accounting for the action of the detector on the system to be measured. We define the full counting statistics of an arbitrary variable by means of an evolution operator that relates initial and final density matrices of the measuring device. In this way we are able to resolve inconsistencies that occur in earlier definitions. We suggest two schemes whereby the so defined full statistics can be observed experimentally.Comment: 11 page