Benoit Gaury

Dynamical control of interference using voltage pulses in the quantum regime

As a general trend, nanoelectronics experiments are shifting towards frequencies so high that they become comparable to the devices internal characteristic time scales, resulting in new opportunities for studying the dynamical aspects of quantum mechanics. Here we theoretically study how a voltage pulse (in the quantum regime) propagates through an electronic interferometer (Fabry-Perot or Mach-Zehnder). We show that extremely fast pulses provide a conceptually new tool for manipulating quantum information: the possibility to dynamically engineer the interference pattern of a quantum system. Striking physical signatures are associated with this new regime: restoration of the interference in presence of large bias voltages; negative currents with respect to the direction of propagation of the voltage pulse; and oscillation of the total transmitted charge with the total number of injected electrons. The present findings have been made possible by the recent unlocking of our capability for simulating time-resolved quantum nanoelectronics of large systems.

The a.c. Josephson effect without superconductivity

Superconductivity derives its most salient features from the coherence of the associated macroscopic wave function. The related physical phenomena have now moved from exotic subjects to fundamental building blocks for quantum circuits such as qubits or single photonic modes. Here we predict that the a.c. Josephson effect—which transforms a d.c. voltage Vb into an oscillating signal cos (2eVbt/ħ)—has a mesoscopic counterpart in normal conductors. We show that when a d.c. voltage Vb is applied to an electronic interferometer, there exists a universal transient regime where the current oscillates at frequency eVb/h. This effect is not limited by a superconducting gap and could, in principle, be used to produce tunable a.c. signals in the elusive 0.1–10-THz ‘terahertz gap’.

Charged Grain Boundaries and Carrier Recombination in Polycrystalline Thin-Film Solar Cells

We present analytical relations for the dark recombination current of a

Depletion region surface effects in electron beam induced current measurements

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A computational approach to quantum noise in time-dependent nanoelectronic devices

junction with positively charged columnar grain boundaries in the high defect density regime. We consider two defect state configurations relevant for positively charged grain boundaries: a single donor state and a continuum of both acceptors and donors. Compared to a continuum of acceptor+donor states, or to the previously studied single acceptor+donor state, the grain boundary recombination of a single donor state is suppressed by orders of magnitude. We show numerically that superposition holds near the open-circuit voltage

Minority-carrier dynamics in semiconductors probed by two-photon microscopy

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Manipulating Andreev and Majorana bound states with microwaves

, so that our dark

Cathodoluminescence Measurements of CdTe in Transmission Electron Microscope

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Classical and quantum spreading of a charge pulse

relations determine

Reprint of : A computational approach to quantum noise in time-dependent nanoelectronic devices

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