Controlled charge pumping in an $\mathrm{Al}\mathrm{Ga}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ gated nanowire by single-parameter modulation is experimentally and theoretically studied. Transfer of integral multiples the elementary per cycle clearly demonstrated. A simple theoretical model shows that such a quantized current can be generated via loading unloading dynamic quasibound state. It demonstrates nonadiabatic blockade unwanted tunnel events obliterate requirement having at least two...

Quantum dots are model systems for quantum thermoelectric behavior because of their ability to control and measure the effects electron-energy filtering confinement on properties. Interestingly, nonlinear properties such small can modify efficiency power conversion. Using embedded in semiconductor nanowires, we thermovoltage thermocurrent that strongly applied thermal bias. We show most observed be understood terms a renormalization quantum-dot energy levels as function bias provide...

Dynamic quantum dots can be formed by time-dependent electrostatic potentials, such as in gate- or surface-acoustic-wave-driven electron pumps. In this work we propose and quantify a scheme to initialize with controllable number of electrons. It is based on rapid increase the potential energy simultaneous decoupling from source lead. The full probability distribution for final captured electrons obtained solving master equation stochastic cascade single escape events. We derive an explicit...

We report noninvasive single-charge detection of the full probability distribution ${P}_{n}$ initialization a quantum dot with $n$ electrons for rapid decoupling from an electron reservoir. analyze data in context model sequential tunneling pinch-off, which has generic solutions corresponding to two opposing mechanisms. One limit considers ``freeze-out'' adiabatically evolving grand canonical distribution, other one is athermal equivalent solution generalized decay cascade model. identify...

The equations-of-motion (EOM) hierarchy satisfied by the Green functions of a quantum dot embedded in an external mesoscopic network is considered within high-order decoupling approximation scheme. Exact analytic solutions resulting coupled integral equations are presented several limits. In particular, it found that at particle-hole symmetric point EOM function temperature-independent due to discontinuous change imaginary part interacting self-energy. However, this obeys Fermi liquid...

This paper investigates a scheme for quantized charge pumping based on single-parameter modulation. The device was realized in an AlGaAs–GaAs gated nanowire. We find remarkable robustness of the regime against variations driving signal, which increases with applied rf power. feature, together its simple configuration, makes this potential module scalable source current.

The two-level model for a double quantum dot coupled to two leads of spinless electrons, which is ubiquitously used describe charge oscillations, transmission-phase lapses and correlation-induced resonances, considered in its general form. features arbitrary tunnelling matrix elements among the levels between themselves (including effect Aharonov-Bohm fluxes), as well interlevel repulsive interactions. We show that this exactly mapped onto generalized Anderson single dot, where electrons...

We study single-parameter quantized charge pumping via a semiconductor quantum dot in high magnetic fields. The is defined between two top gates an AlGaAs/GaAs heterostructure. Application of oscillating voltage to one the leads pumped current plateaus gate characteristic, corresponding controlled transfer integer multiples electrons per cycle. In perpendicular-to-plane field become more pronounced indicating improved quantization. Current quantization sustained up fields where full spin...

We report an experimental technique to measure and manipulate the arrival-time energy distributions of electrons emitted from a semiconductor electron pump, operated as both single-electron source two-electron source. Using energy-selective detector whose transmission we control on picosecond timescales, can directly distribution determine upper-bound width be 30 ps. study effects modifying shape voltage waveform that drives show our results explained by tunneling model emission mechanism....

Quantum pumping through mesoscopic quantum dots is known to be enhanced by resonant transmission. The pumped charge close an integer number of electrons when the contour surrounds a resonance, but transmission remains small on contour. For non-interacting electrons, we give quantitative account detailed exchange between dot and leads (to electron reservoirs) during cycle. Near isolated distinct resonances, use approximate Breit-Wigner expressions for dot's Green function discuss...

We investigate charge pumping in carbon nanotube quantum dots driven by the electric field of a surface acoustic wave. find that, at small driving amplitudes, pumped current reverses polarity as conductance is tuned through Coulomb blockade peak using gate electrode. study behavior function wave amplitude, frequency, and direction develop model which our results can be understood resulting from adiabatic redistribution between leads on nanotube.

The phase of a single quantum state is undefined unless the history its creation provides reference point. Thus interference may seem hardly relevant for design deterministic single-electron sources which strive to isolate individual charge carriers quickly and completely. We provide counterexample by analyzing non-adiabatic separation localized from Fermi sea due closing tunnel barrier. identify energy scales suggest ways separate contributions excitation backtunneling rare non-capture...

Synchrotron radiation-based nano-FTIR spectroscopy utilizes the highly brilliant and ultra-broadband infrared (IR) radiation provided by electron storage rings for spectroscopic characterization of samples at nanoscale. In order to exploit full potential this approach we investigated influence properties source, such as bunch shape spectral bandwidth emitted radiation, on near-field spectra silicon-carbide (SiC). The adapted configuration ring optics enables a modification transverse profile...

We operate an on-demand source of single electrons in high perpendicular magnetic fields up to 30T, corresponding a filling factor below 1/3. The device extracts and emits charges at tunable energy from two-dimensional electron gas, brought into well defined integer fractional quantum Hall (QH) states. It can therefore be used for sensitive electrical transport studies, e.g. excitations relaxation processes QH edge

A method for characterising the wave-function of freely-propagating particles would provide a useful tool developing quantum-information technologies with single electronic excitations. Previous continuous-variable quantum tomography techniques developed to analyse excitations in energy-time domain have been limited energies close Fermi level. We show that wideband single-particle distributions is possible using filtering and Wigner representation mixed-state density matrix can be...

We study a mesoscopic circuit of two quantized current sources, realized by nonadiabatic single-electron pumps connected in series with small micron-sized island between. find that quantum transport through the second pump can be locked onto first one feedback due to charging island. This is confirmed measurement charge variation on using nearby detector. Finally, signal clearly evidences loading into excited states dynamic dot during operation.

We present a comprehensive first-principles study of the electronic charge redistribution in atomically sharp LaAlO$_3$/SrTiO$_3$(001) heterointerfaces both n- and p-types allowing for non-stoichiometric composition. Using two different computational methods within framework density functional theory (linear combination atomic orbitals plane waves) we demonstrate that conducting properties strongly depend on termination LaAlO$_3$ (001) surface. argue polar "catastrophe" distortion scenarios...

Experiments on collisions of isolated electrons guided along the edges in quantum Hall setups can mimic mixing photons with important distinction that are charged fermions. In so-called electronic Hong-Ou-Mandel (HOM) setup uncorrelated pairs injected towards a beamsplitter. If two electron wave packets were identical, Fermi statistics would force to scatter different detectors, yet this antibunching may be confounded by Coulomb repulsion. Here we model an HOM experiment using quadratic 2D...

Understanding the charging of exceptionally narrow levels in quantum dots presence interactions remains a challenge within mesoscopic physics. We address this fundamental question generic model level capacitively coupled to broad one. Using bosonization we show that for arbitrary capacitive coupling can be described by an analogy magnetization anisotropic Kondo model, featuring low-energy crossover scale depends power-law fashion on tunneling amplitude level. Explicit analytical expressions...

Emergence of universal collective behaviour from interactions in a sufficiently large group elementary constituents is fundamental scientific paradigm. In physics, correlations fluctuating microscopic observables can provide key information about states matter such as deconfined quark-gluon plasma heavy-ion collisions or expanding quantum degenerate gases. Two-particle mesoscopic colliders have provided smoking-gun evidence on the nature exotic electronic excitations fractional charges,...

Emergence of a classical particle trajectory concept from the full quantum description is key feature mechanics. Recent progress solid-state on-demand sources has brought single-electron manipulation into regime; however, quantum-to-classical crossover remains unprobed. Here we describe theoretically mechanism for generating wave packets by tunneling driven localized state, and show how to tune degree quantumness. Applying our theory existing sources, demonstrate feasibility an experimental...