English
Related papers

Related papers: Levitons in superconducting point contacts

200 papers

We consider the electromagnetic field generated by a coherent conductor in which electron transport is described quantum mechanically. We obtain an input-output relation linking the quantum current in the conductor to the measured…

Mesoscale and Nanoscale Physics · Physics 2016-02-03 Farzad Qassemi , Arne L. Grimsmo , Bertrand Reulet , Alexandre Blais

We derive a formula for the current through an interacting quantum dot coupled to two supercouducting leads, using the non-equilibrium Green's function formalism. It is shown that the formula takes an especially simple form, when the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Kicheon Kang

Inherent randomness and the resulting stochastic behavior of fundamental particles manifested as quantum noise put a lower bound on measurement imprecision in the quantum measurement process. In addition, the quantum noise imparts…

Mesoscale and Nanoscale Physics · Physics 2025-01-22 Prasanta Kumbhakar , Anusha Shanmugam , Akhileshwar Mishra , Ravi Pant , J L Reno , S Addamane , Madhu Thalakulam

We discuss intrinsic mechanisms of nonequilibrium excess noise in superconducting devices and transition edge sensors. In particular, we present an overview of fluctuation-driven contributions to the current noise in the vicinity of the…

Superconductivity · Physics 2023-08-25 Juhun Kwak , Emil Pellett , Elio J. König , Alex Levchenko

Charge transfer in a tunnel junction is studied under dc and ac voltage bias using quantum shot noise. Under dc voltage bias $V$, spectral density of noise measured within a very large bandwidth enables to deduce the current-current…

Mesoscale and Nanoscale Physics · Physics 2017-02-16 Julien Gabelli , Karl Thibault , Gabriel Gasse , Christian Lupien , Bertrand Reulet

Peculiar electronic properties of graphene, including the universal dc conductivity and the pseudodiffusive shot noise, are usually attributed to a small vicinity of the charge-neutrality point, away from which electron's effective mass…

Mesoscale and Nanoscale Physics · Physics 2025-05-01 Adam Rycerz

We study theoretically electronic transport through a contact of a quantum wire with 2D or 3D leads and find that if the contact is not smooth and adiabatic then the conduction is strongly suppressed below a threshold voltage $V_T$, while…

Mesoscale and Nanoscale Physics · Physics 2015-10-01 S. N. Artemenko , P. P. Aseev , D. S. Shapiro

We investigate minimal excitation states for heat transport into a fractional quantum Hall system driven out of equilibrium by means of time-periodic voltage pulses. A quantum point contact allows for tunneling of fractional quasi-particles…

Mesoscale and Nanoscale Physics · Physics 2017-06-16 Luca Vannucci , Flavio Ronetti , Jérôme Rech , Dario Ferraro , Thibaut Jonckheere , Thierry Martin , Maura Sassetti

A hydrodynamic theory of transport in quantum mechanically phase-disordered superconductors is possible when supercurrent relaxation can be treated as a slow process. We obtain general results for the frequency-dependent conductivity of…

Superconductivity · Physics 2017-08-03 Richard A. Davison , Luca V. Delacrétaz , Blaise Goutéraux , Sean A. Hartnoll

We develop a very general perturbative theory of time-dependent transport in a weak tunneling junction which is independent of experimental details and on many-body correlated states in the coupled conductors. These can be similar or…

Mesoscale and Nanoscale Physics · Physics 2014-01-24 Ines Safi

We study theoretically the electron transport in a 1D conductor adiabatically connected to a superconducting and normal metal leads. In the case of non-interacting we show that ac voltage applied along with dc voltage modifies I-V curve…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 P. P. Aseev , S. N. Artemenko

The specific property of a planar tunnel junction with thin-film diffusive plates and long enough leads is an essential enhancement of its transmission coefficient compared to the bare transparency of the tunnel barrier [1,2]. In…

Superconductivity · Physics 2017-01-04 E. V. Bezuglyi , A. S. Vasenko , E. N. Bratus'

It is shown, with citing tunnel junction as an example, that mutual interplay of electron quantum transfers in a conducting system can be the fast mechanism for generation fundamental low-frequency flicker conductance fluctuations (1/f…

Statistical Mechanics · Physics 2007-05-23 Yu. E. Kuzovlev , Yu. V. Medvedev , A. M. Grishin

We propose a theoretical model for the low-frequency noise observed in a quantum point contact (QPC) electrostatically defined in the 2D electron gas at a GaAs-AlGaAs interface. In such contacts electron scattering by soft impurity- or…

Condensed Matter · Physics 2009-10-22 J. P. Hessling , Yu. Galperin , M. Jonson , R. I. Shekhter , A. M. Zagoskin

We report measurements of the low frequency current fluctuations of a tunnel junction placed at very low temperature biased by a time-dependent voltage $V(t)=V(1+\cos 2\pi\nu t)$. We observe that the excess noise generated by the ac…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Gabriel Gasse , Lafe Spietz , Christian Lupien , Bertrand Reulet

Precise shaping of coherent electron sources allows the controlled creation of wavepackets into a one dimensional (1D) quantum conductor. Periodic trains of Lorentzian pulses have been shown to induce minimal excitations without creating…

Mesoscale and Nanoscale Physics · Physics 2019-10-17 Matteo Acciai , Alessio Calzona , Matteo Carrega , Thierry Martin , Maura Sassetti

In circuit quantum electrodynamical systems, the quasiparticle-related losses in Josephson junctions are suppressed due to the gap in the superconducting density of states which is much higher than the typical energy of a microwave photon.…

Quantum Physics · Physics 2025-10-08 Vasilii Vadimov , Yoshiki Sunada , Mikko Möttönen

Under nonequilibrium conditions, quantum optical systems reveal unusual properties that might be distinct from those in condensed matter. The fundamental reason is that photonic eigenstates can have arbitrary occupation numbers, whereas in…

Quantum Physics · Physics 2021-07-06 Dmitriy S. Shapiro

We consider a quantum dot coupled to two BCS superconductors with same gap energies $\Delta$. The transport properties are investigated by means of infinite-$U$ noncrossing approximation. In equilibrium density of states, Kondo effect shows…

Superconductivity · Physics 2016-08-31 S. Y. Liu , X. L. Lei

Employing a real time effective action formalism we analyze electron transport and current fluctuations in comparatively short coherent conductors in the presence of electron-electron interactions. We demonstrate that, while Coulomb…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Dmitri S. Golubev , Artem V. Galaktionov , Andrei D. Zaikin