Related papers: Supercurrent reversal in quantum dots
We analyze cotunneling transport through two quantum dots in series weakly coupled to external ferromagnetic leads. In the Coulomb blockade regime the electric current flows due to third-order tunneling, while the second-order…
There are several ways to turn a superconductor into a normal conductor: increase the temperature, apply a high magnetic field, or run a large current. High-T$_c$ cuprate superconductors are unusual in the sense that experiments suggest…
We investigate the Josephson effect through a two-level quantum dot with an exchange coupling between two dot electrons. We compute the superconducting phase relationship and construct the phase diagram in the superconducting gap--exchange…
VI-curves of resistively shunted single Josephson junctions with different capacitances and tunneling resistances are found to display a crossover between two types of VI-curves: one without and another with a resistance bump (negative…
We analyze the charge transport through a single level quantum dot coupled to a normal (N) and superconducting (S) leads where the electron pairs exist either as the coherent (for temperatures below T_c) or incoherent objects (in a region…
We study the transient phenomena appearing in a subgap region of the double quantum dot coupled in series between the superconducting and normal metallic leads, focusing on the development of the superconducting proximity effect. For the…
We predict two novel quantum drag effects which can occur in macroscopically quantum coherent Josephson circuits. We demonstrate that biasing one resistively shunted Josephson junction by an external current one can induce a non-zero…
Superconductivity with spin-polarized Cooper pairs is known to emerge by combining conventional spinless superconductors with materials that have spin-dependent interactions, such as magnetism and spin-orbit coupling. This enables a…
We consider the sub-gap physics of a hybrid double-quantum dot Cooper-pair splitter with large single-level spacings, in the presence of tunnelling between the dots and finite Coulomb intra- and inter-dot Coulomb repulsion. In the limit of…
We study the interplay of spin and charge coherence in a single-level quantum dot. A tunnel coupling to a superconducting lead induces superconducting correlations in the dot. With full spin symmetry retained, only even-singlet…
We investigate two equivalent, capacitively coupled semiconducting quantum dots, each coupled to its own lead, in a regime where there are two electrons on the double dot. With increasing interdot coupling a rich range of behavior is…
We report low-temperature transport experiments on single-wall nanotubes with metallic leads of varying contact quality, ranging from weak tunneling to almost perfect transmission. In the weak tunneling regime, where Coulomb blockade…
We study a two-terminal graphene Josephson junction with contacts shaped to form a narrow constriction, less than 100nm in length. The contacts are made from type II superconducting contacts and able to withstand magnetic fields high enough…
We investigate cross-correlations in the tunneling currents through two parallel quantum dots coupled to independent electrodes and gates and interacting via an inter-dot Coulomb interaction. The correlations reveal additional information,…
We inspect signatures of dynamical quantum phase transitions driven by two types of quenches acting on a correlated quantum dot embedded between superconducting and metallic reservoirs. Under stationary conditions the proximity induced…
It is demonstrated that non local Cooper pairs can propagate in ferromagnetic electrodes having an opposite spin orientation. In the presence of such crossed correlations, the superconducting gap is found to depend explicitly on the…
We report on a novel Kondo phenomenon of interacting quantum dots coupled asymmetrically to a normal and a superconducting lead. The effects of intradot Coulomb interaction and Andreev tunneling give rise to Andreev bound resonances. As a…
The Coulomb drag phenomenon in a Coulomb-coupled double quantum dot system is revisited with a simple model that highlights the importance of simultaneous tunneling of electrons. Previously, cotunneling effects on the drag current in…
Electron transport through a quantum dot chain with two neighboring dots coupled to both leads is theoretically studied. In such a system, it is found that only for the even-numbered quantum dot structure with the same-number quantum dots…
The superconductor to insulator or metal transition in two dimensions (2D) provides a valuable platform for studying continuous quantum phase transitions (QPTs) and critical phenomena. Distinct theoretical models, including both fermionic…