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Related papers: Supercurrent noise in quantum point contacts

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We theoretically investigate the phase and voltage correlation dynamics, which includes both the deterministic contribution and stochastic fluctuations, under a current noise generated by a resistor including thermal and quantum…

Mesoscale and Nanoscale Physics · Physics 2021-07-27 Koichiro Furutani , Luca Salasnich

We present a new analysis of shot noise measurements in normal metal-superconductor (NS) junctions [X. Jehl et al., Nature 405, 50 (2000)], based on a recent semiclassical theory. The first calculations at zero temperature assuming quantum…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 X. Jehl , M. Sanquer

A singularity at the Josephson frequency in the noise spectral density of a disordered normal metal -- superconductor junction is predicted for bias voltages below the superconducting gap. The non-stationary Aharonov-Bohm effect, recently…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Gordey B. Lesovik , Thierry Martin , Julien Torres

The statistics of quantum transport in nanostructures can be tailored by a time-dependent bias voltage $V(t)$. We demonstrate experimentally how correlations of current fluctuations at two different times $t$ and $t+\tau$ depend on the…

Mesoscale and Nanoscale Physics · Physics 2024-04-16 Jean-Olivier Simoneau , Sébastien Jezouin , Christian Lupien , Bertrand Reulet

We study mesoscopic fluctuations and weak localization correction to the supercurrent in Josephson junctions with coherent diffusive electron dynamics in the normal part. Two kinds of junctions are considered: a chaotic dot coupled to…

Mesoscale and Nanoscale Physics · Physics 2008-03-10 M. Houzet , M. A. Skvortsov

Electronic transport through nanostructures is greatly affected by the presence of superconducting leads. If the interface between the nanostructure and the superconductors is sufficiently transparent, a dissipationless current…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Pablo Jarillo-Herrero , Jorden A. van Dam , Leo P. Kouwenhoven

By coupling a quantum detector, a superconductor-insulator-superconductor junction, to a Josephson junction \textit{via} a resonant circuit we probe the high frequency properties, namely the ac complex admittance and the current…

Mesoscale and Nanoscale Physics · Physics 2012-03-02 Julien Basset , Hélène Bouchiat , Richard Deblock

Recently, a new theory of superconductivity has been put forward that attributes the origin of superconductivity to the appearance of a non-trivial Berry connection from many-electron wave functions. This theory reproduces the major results…

Superconductivity · Physics 2024-03-14 Hiroyasu Koizumi

We study a Josephson junction (JJ) in the regime of incoherent Cooper pair tunneling, capacitively coupled to a nonequilibrium noise source. The current-voltage (I-V) characteristics of the JJ are sensitive to the excess voltage…

Mesoscale and Nanoscale Physics · Physics 2013-04-04 Tero T. Heikkila , Pauli Virtanen , Goran Johansson , Frank K. Wilhelm

Solid-state systems which mimic two-level atoms are being actively developed. Improving the quantum coherence of these systems, for instance spin qubits or single photon emitters using semiconductor quantum dots, involves dealing with…

We report on long-term measurements of a highly coherent, non-tunable superconducting transmon qubit, revealing low-frequency burst noise in coherence times and qubit transition frequency. We achieve this through a simultaneous measurement…

We study decoherence of the Josephson charge qubit by measuring energy relaxation and dephasing with help of the single-shot readout. We found that the dominant energy relaxation process is a spontaneous emission induced by quantum noise…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 O. Astafiev , Yu. A. Pashkin , Y. Nakamura , T. Yamamoto , J. S. Tsai

We show how to calculate the charge noise spectrum in a normal mesoscopic conductor, which is capacitively coupled to a macroscopic gate, when this conductor is attached to L normal leads and M superconducting leads, the only restriction…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Andrew M. Martin , Thomas Gramespacher , Markus Buttiker

Quantum phase slips (QPS) may produce non-equilibrium voltage fluctuations in current-biased superconducting nanowires. Making use of the Keldysh technique and employing the phase-charge duality arguments we investigate such fluctuations…

Superconductivity · Physics 2017-05-11 Andrew G. Semenov , Andrei D. Zaikin

We discuss the use of a hysteretic Josephson junction to detect current fluctuations with frequencies below the plasma frequency of the junction. These adiabatic fluctuations are probed by switching measurements observing the noise-affected…

Mesoscale and Nanoscale Physics · Physics 2010-03-29 J. T. Peltonen , A. V. Timofeev , M. Meschke , J. P. Pekola

We compute the decoherence caused by $1/f$ fluctuations at low frequency $f$ in the critical current $I_0$ of Josephson junctions incorporated into flux, phase, charge and hybrid flux-charge superconducting quantum bits (qubits). The…

We analyze charge tunneling statistics and current noise in a superconducting single-electron transistor in a regime where the Josephson-quasiparticle cycle is the dominant mechanism of transport. Due to the interplay between Coulomb…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Mahn-Soo Choi , Francesco Plastina , Rosario Fazio

We consider a single-level quantum dot tunnel-coupled to one normal and one superconducting lead. We employ a diagrammatic real-time approach to calculate the finite-frequency current noise for subgap transport. The noise spectrum gives…

Mesoscale and Nanoscale Physics · Physics 2015-04-14 Stephanie Droste , Janine Splettstoesser , Michele Governale

The dc Josephson effect in a superconducting quantum point contact, where supercurrent flows through a small number of channels, is reviewd. The central role of Andreev levels is emphasized which carry the whole supercurrent in short…

Superconductivity · Physics 2009-10-31 A. Furusaki

We study the current noise spectra of a tunnel junction of a metal with strong pairing phase fluctuation and a superconductor. It is shown that there is a characteristic peak in the noise spectrum at the intrinsic Josephson frequency…

Strongly Correlated Electrons · Physics 2009-10-31 Xi Dai , Tao Xiang , Tai-Kai Ng , Zhao-bin Su