Related papers: Reversing the sign of current-current correlations
Exact analytical formulas are derived, by means of Keldysh Green functions, for currents and current correlation functions in a Cooper pair splitter modelled on a double quantum dot system coherently coupled to a superconductor and two…
The dynamics of a single spin embedded in a the tunnel junction between ferromagnetic contacts is strongly affected by the exchange coupling to the tunneling electrons. Moment reversal of the local spin induced by the bias voltage across…
We consider the problem of interacting electrons constrained to move on a fluctuating one-dimensional string. An effective low-energy theory for the electrons is derived by integrating out the string degrees of freedom to lowest order in…
We investigate electron transport in two quantum circuits with mutual Coulomb interaction. The first circuit is a double quantum dot connected to two electron reservoirs, while the second one is a quantum point contact in the weak tunneling…
We study theoretically the contribution of fluctuating Cooper pairs to the persistent current in superconducting rings threaded by a magnetic flux. For sufficiently small rings, in which the coherence length $\xi$ exceeds the radius $R$,…
We study transport in coherent conductors driven by a time-periodic bias voltage. We present results of the charge and energy noise and complement them by a study of the mixed noise, namely the zero-frequency correlator between charge and…
The energetic properties of electron transport in mesoscopic and nanoscale conductors is of large current interest. Here we theoretically investigate the possibility of probing fluctuations of charge and heat currents as well as their mixed…
We study the current statistics in normal diffusive conductors in contact with a superconductor. Using an extension of the Keldysh Green's function method we are able to find the full distribution of charge transfers for all temperatures…
We report the theory of the \emph{dynamical response of current fluctuations} of a photo-excited conductor. We have performed the calculation for a coherent conductor described by arbitrary energy-dependent transmissions and for arbitrary…
Quantum fluctuations are ubiquitous in physics. Ranging from conventional examples like the harmonic oscillator to intricate theories on the origin of the universe, they alter virtually all aspects of matter -- including superconductivity,…
We study a resistively and capacitively shunted Josephson junction, which is driven by a combination of time-periodic and constant currents. Our investigations concern three main problems: (A) The voltage fluctuations across the junction;…
It is shown that the spin resolved current shot noise can probe attractive or repulsive interactions in mesoscopic systems. This is illustrated in two physical situations : i) a normal-superconducting junction where the spin current noise…
The detection of elementary carriers in transport phenomena is one of the most important keys to understand non-trivial properties of strongly-correlated quantum matter. Here we propose a method to identify the tunneling current carrier in…
Superconducting nanowires and Josephson junctions, when biased close to superconducting critical current, can switch to a non-zero voltage state by thermal or quantum fluctuations. The process is understood as an escape of a Brownian…
Describing current in open quantum systems can be problematic due to the subtle interplay of quantum coherence and environmental noise. Probing the noise-induced current can be detrimental to the tunneling-induced current and vice versa. We…
Spectral density of current fluctuations in a short ballistic superconducting quantum point contact is calculated for arbitrary bias voltages $V$. Contrary to a common opinion that the supercurrent flow in Josephson junctions is coherent…
Scanning tunneling miscoscopy is one of the most powerful spectroscopic tools for single-electron excitations. We show that the conductance fluctuations, or noise in the conductance, of a tunneling current into an interacting electron…
The parametrically pumped Kerr model describes a driven-dissipative nonlinear cavity, whose nonequilibrium phase diagram features both continuous and discontinuous quantum phase transitions. We consider the consequences of these critical…
We study consequences of gauge invariance and charge conservation of an electron gas in a strong random potential perturbed by a weak electromagnetic field. We use quantum equations of motion and Ward identities for one- and two-particle…
The recent discovery of intrinsic supercurrent diode effect, and its prompt observation in a rich variety of systems, has shown that nonreciprocal supercurrents naturally emerge when both space- and time-inversion symmetries are broken. In…