Proposal for non-local electron-hole turnstile in the Quantum Hall regime

We present a theory for a mesoscopic turnstile that produces spatially separated streams of electrons and holes along edge states in the quantum Hall regime. For a broad range of frequencies in the non-adiabatic regime the turnstile operation is found to be ideal, producing one electron and one hole per cycle. The accuracy of the turnstile operation is characterized by the fluctuations of the transferred charge per cycle. The fluctuations are found to be negligibly small in the ideal regime.Comment: 4+ pages, 2 figure

Full counting statistics of incoherent Andreev transport

We study the full counting statistics of heterostructures consisting of normal metal parts connected to a superconducting terminal. Assuming that coherent superconducting correlations are suppressed in the normal metals we show, using Keldysh-Nambu Green's functions, that the system can be mapped onto a purely normal system with twice the number of elements. For a superconducting beam splitter with several normal terminals we obtain general results for the counting statistics.Comment: 7 pages, submitted to Europhys. Let

Multiple Andreev reflections in hybrid multiterminal junctions

We investigate theoretically charge transport in hybrid multiterminal junctions with superconducting leads kept at different voltages. It is found that multiple Andreev reflections involving several superconducting leads give rise to rich subharmonic gap structures in the current-voltage characteristics. The structures are evidenced numerically in junctions in the incoherent regime.Comment: 5 pages, 3 figure

Sub Decoherence Time Generation and Detection of Orbital Entanglement

Recent experiments have demonstrated sub decoherence time control of individual single-electron orbital qubits. Here we propose a quantum dot based scheme for generation and detection of pairs of orbitally entangled electrons on a timescale much shorter than the decoherence time. The electrons are entangled, via two-particle interference, and transferred to the detectors during a single cotunneling event, making the scheme insensitive to charge noise. For sufficiently long detector dot lifetimes, cross-correlation detection of the dot charges can be performed with real-time counting techniques, opening up for an unambiguous short-time Bell inequality test of orbital entanglement.Comment: 5 pages, 2 figures, 3 pages supplemental materia

Quantized dynamics of a coherent capacitor

A quantum coherent capacitor subject to large amplitude pulse cycles can be made to emit or reabsorb an electron in each half cycle. Quantized currents with pulse cycles in the GHz range have been demonstrated experimentally. We develop a non-linear dynamical scattering theory for arbitrary pulses to describe the properties of this very fast single electron source. Using our theory we analyze the accuracy of the current quantization and investigate the noise of such a source. Our results are important for future scientific and possible metrological applications of this source.Comment: 4 pages, 2 figure

Nanoscale Quantum Calorimetry with Electronic Temperature Fluctuations

Motivated by the recent development of fast and ultra-sensitive thermometry in nanoscale systems, we investigate quantum calorimetric detection of individual heat pulses in the sub-meV energy range. We propose a hybrid superconducting injector-calorimeter set-up, with the energy of injected pulses carried by tunneling electrons. Treating all heat transfer events microscopically, we analyse the statistics of the calorimeter temperature fluctuations and derive conditions for an accurate measurement of the heat pulse energies. Our results pave the way for novel, fundamental quantum thermodynamics experiments, including calorimetric detection of single microwave photons.Comment: 6 pages, 3 figures plus supplemental material, 8 pages, 1 figur

Quantum heat fluctuations of single particle sources

Optimal single electron sources emit regular streams of particles, displaying no low frequency charge current noise. Due to the wavepacket nature of the emitted particles, the energy is however fluctuating, giving rise to heat current noise. We investigate theoretically this quantum source of heat noise for an emitter coupled to an electronic probe in the hot-electron regime. The distribution of temperature and potential fluctuations induced in the probe is shown to provide direct information on the single particle wavefunction properties and display strong non-classical features.Comment: 5 pages, 2 figure