Related papers: Quantum Charge Fluctuations in a Superconducting G…
The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where…
The conductance in Coulomb blockade quantum dots exhibits sharp peaks whose spacings fluctuate with the number of electrons. We derive the temperature-dependence of these fluctuations in the statistical regime and compare with recent…
We study Coulomb blockade (CB) oscillations in the thermodynamics of a metallic grain which is connected to a lead by a tunneling contact with a large conductance $g_0$ in a wide temperature range, $E_Cg_0^4 e^{-g_0/2}<T<E_C$, where $E_C$…
Electron tunneling through mesoscopic metallic grains can be treated perturbatively only provided the tunnel junction conductances are sufficiently small. If it is not the case, fluctuations of the grain charge become strong. As a result…
I study the effect of Coulomb interaction on superconducting order in a d-wave lattice superconductor at T=0 by considering the superconducting saddle point in the two dimensional t-J-U model with an on-site repulsion U. The theory of low…
The smaller the system, typically - the higher is the impact of fluctuations. In narrow superconducting wires sufficiently close to the critical temperature Tc thermal fluctuations are responsible for the experimentally observable finite…
Properties of the Kondo effect in quantum dots depend sensitively on the coupling parameters and so on the realization of the quantum dot -- the Kondo temperature itself becomes a mesoscopic quantity. Assuming chaotic dynamics in the dot,…
The noncrossing approximation (NCA) is generalized to the multi-channel Kondo-spin Hamiltonian with arbitrary anisotropic exchange couplings and an external magnetic field, and applied -- in the framework of Matveev's mapping -- to the…
We derive the $\sigma$-model for granular metals. It is valid for any relation between the temperature, $T$, and the grain mean level spacing. The continuum limit of the $\sigma$-model describes non-perturbative charging effects in…
We study fluctuations of conductance of two connected in series dots in the Coulomb blockade regime. The pattern of the fluctuations turns out to be extremely sensitive to a magnetic field. These conductance fluctuations also provide…
We describe electron transport through small metallic grains with Coulomb blockade effects beyond the perturbative regime. For this purpose we study the real-time evolution of the reduced density matrix of the system. In the first part of…
We study drag effect in a system of two electrically isolated quantum point contacts (QPC), coupled by Coulomb interactions. Drag current exhibits maxima as a function of QPC gate voltages when the latter are tuned to the transitions…
Recently, superconductivity has been observed in twisted WSe$_2$ moir\'{e} structures (Xia et al., Nature 2024; Guo et al., Nature 2025). Its transition temperature is high, reaching a few percent of the Fermi temperature scale. Here, we…
Time dependent phenomena associated to charge transport along a quantum dot in the charge quantization regime is studied. Superimposed to the Coulomb blockade behaviour the current has novel non-linear properties. Together with static…
In 1909, Millikan showed that the charge of electrically isolated systems is quantized in units of the elementary electron charge e. Today, the persistence of charge quantization in small, weakly connected conductors allows for circuits…
We investigate non-equilibrium transport properties of a quantum dot in the Coulomb blockade regime under the condition of negligible inelastic scattering during the dwelling time of the electrons in the dot. Using the quantum kinetic…
We examine a quantum dot with $N_{\rm dot}$ levels which is strongly coupled to leads for varying number of channels $N$ in the leads. It is shown both analytically and numerically that for strong couplings between the dot and the leads, at…
We consider a quantum battery modeled as a set of N independent two-level quantum systems driven by a time dependent classical source. Different figures of merit, such as stored energy, time of charging and energy quantum fluctuations…
We review the mechanisms of low-temperature electron transport across a quantum dot weakly coupled to two conducting leads. Conduction in this case is controlled by the interaction between electrons. At temperatures moderately lower than…
We analyze ground-state properties of a large gated quantum dot coupled via a quantum point contact to a reservoir of one-dimensional interacting spinless electrons. We find that the classical step-like dependence of the dot population on…