Related papers: Andreev bound states probed in three-terminal quan…
Hybrid superconductor-semiconducting nanowire devices provide an ideal platform to investigating novel intragap bound states, such as the Andreev bound states (ABSs), Yu-Shiba-Rusinov (YSR) states, and the Majorana bound states. The…
We report on high-resolution differential conductance experiments on nanoscale superconductor/ferromagnet tunnel junctions with ultra-thin oxide tunnel barriers. We observe subgap conductance features which are symmetric with respect to…
We analyze Andreev bound states (ABSs) that form in normal sections of a Rashba nanowire that is only partially covered by a superconducting layer. These ABSs are localized close to the ends of the superconducting section and can be pinned…
Electronic excitations above the ground state must overcome an energy gap in superconductors with spatially-homogeneous s-wave pairing. In contrast, inhomogeneous superconductors such as those with magnetic impurities or weak links, or…
We study coherent transport and bound-state formation of Bogoliubov quasiparticles in a high-mobility In$_{0.75}%$Ga$_{0.25}$As two-dimensional electron gas (2DEG) coupled to a superconducting Nb electrode by means of a quantum point…
Andreev bound states (ABS) at the surface of superconductors are expected for any pair potential showing a sign change in different k-directions with their spectral weight depending on the relative orientation of the surface and the pair…
Transport studies of Andreev bound states (ABSs) are complicated by the interplay of charging effects and superconductivity. Here, we compare transport approaches to ABS spectroscopy in a semiconductor-superconductor island to a…
The formation of bound states at surfaces of materials with an energy gap in the bulk electron spectrum is a well known physical phenomenon. At superconductor surfaces, quasiparticles with energies inside the superconducting gap $\Delta$…
Many of the properties of superconductors related to quantum coherence are revealed when the superconducting state is forced to vary in space - in response to an external magnetic field, a proximity contact, an interface to a ferromagnet,…
We theoretically analyze non-local effects in electron transport across three-terminal ballistic normal-superconducting-normal (NSN) structures with spin-active interfaces. Subgap electrons entering S-electrode from one N-metal may form…
We design and investigate an experimental system capable of entering an electron transport blockade regime in which a spin-triplet localized in the path of current is forbidden from entering a spin-singlet superconductor. To stabilize the…
A short superconducting segment can couple attached quantum dots via elastic co-tunneling (ECT) and crossed Andreev reflection (CAR). Such coupled quantum dots can host Majorana bound states provided that the ratio between CAR and ECT can…
Motivated by experimental observation of the Kondo-enhanced Andreev transport [R. S. Deacon \textit{et al.}, PRB \textbf{81}, 121308(R) (2010)] in a hybrid normal metal-quantum dot-superconductor (N-QD-S) device, we theoretically study the…
We study Andreev transport through double quantum dots connected in series normal and superconducting (SC) leads, using the numerical renormalization group. The ground state of this system shows a crossover between a local Cooper-pairing…
While Andreev bound states (ABSs) have been realized in engineered superconducting junctions, their direct observation in normal metal/superconductor heterostructures-enabled by quantum confinement-remains experimentally elusive. Here, we…
In this PhD thesis, quantum devices based on molecular-beam epitaxy grown InAs semiconductor with an in-situ grown epitaxial Al film were investigated. Novel device geometries were realized that allow for the study of bound states that…
We analyze non-local effects in electron transport across three-terminal normal-superconducting-normal (NSN) structures. Subgap electrons entering S-electrode from one N-metal may form Cooper pairs with their counterparts penetrating from…
We investigate theoretically the Andreev transport through a quantum dot strongly coupled with a normal metal/ferromagnet and a superconductor (N/F-QD-S), in which the interplay between the Kondo resonance and the Andreev bound states…
A recently developed theory for the problem of Andreev reflection between a normal metal (N) and a multiband superconductor (MBS) assumes that the incident wave from the normal metal is coherently transmitted through several bands inside…
This paper reviews the confinement-driven phase transitions, and the prediction of superfluid phases with broken time-reversal or translational symmetry in thin films. The new phases are a result of particle-hole coherent Andreev scattering…