Superconductivity
Josephson junctions are key elements in superconducting electronics. The most common type is the overlap (sandwich-type) junction, formed by vertically stacking two superconducting layers. In contrast, planar junctions are fabricated…
Two decades since its discovery, superconducting heavily boron-doped diamond (HBDD) still presents unresolved fundamental questions whose resolution is relevant to the development of this material for quantum technologies. We use electrical…
Josephson diodes (JDs) offer a promising route towards realizing dissipation-less rectification at low temperatures. To be practically viable, a JD must operate at zero magnetic fields, exhibit high operating frequencies and efficiency, and…
Clarifying the magnetic ground state is essential for analysing unconventional superconductivity, because microscopic magnetic order provides one of the basic starting assumptions for spin-fluctuation pairing theories. FeSe exhibits…
Nematicity in LaFeAsO single crystals is studied by means of high-resolution thermal expansion, shear modulus, and elastoresistivity measurements. A softening of the shear modulus $C_{\rm 66}$ towards the structural phase transition at…
Electronic bands in systems with space-time inversion (IST) symmetry can host nontrivial Euler topology. Here, we investigate the band topology of IST-symmetric superconducting honeycomb lattices and demonstrate that s-wave spin-singlet…
Bilayer Ruddlesden-Popper nickelates display superconductivity near 80 K under high pressure, establishing a new nickelate platform for studying unconventional high-temperature superconductivity. The recent stabilization of superconducting…
For decades, superconductivity in high-Tc cuprates has been viewed as a competitor that suppresses charge-density-wave (CDW) order by reducing its amplitude and spatial extent. Here, we show that this picture is incomplete, as…
Topological superconductivity has attracted great interest due to its fundamental significance for realizing Majorana quasiparticles and fault-tolerant quantum computation. Nonsymmorphic superconductors, with symmetry-protected nontrivial…
When a superconductor is placed in contact with a normal material, Cooper pairs penetrate the latter and induce superconductivity via the proximity effect. Despite its central role in quantum materials, superconducting devices and…
While magnetic fields and superconductors are both central to classical and quantum technologies, their combined use is often challenging, as magnetic fields significantly affect superconducting device performance. In superconducting…
The Meissner effect is the expulsion of magnetic flux from the interior of a bulk superconductor in the presence of the constant critical magnetic field by the persistent current circulating near the surface of the superconductor. The…
We develop a Ginzburg--Landau theory for superconducting thin films under quantum confinement. Starting from the microscopic BCS free energy and the recently developed confinement theory of metallic thin films, explicit analytical…
The relative phase between the two pair condensates of a bilayer s-wave superconductor is a collective degree of freedom distinct from the usual in-phase Anderson-Bogoliubov mode. Working at the Gaussian fluctuation level for the AA-stacked…
This work presents the development and testing of a novel radio-frequency (RF) gasket with a Lenz lens surface geometry for contactless measurements in diamond anvil cells (DACs). Conventional RF approaches, which fabricate the Lenz lens…
Flat-band superconductors provide a regime in which kinetic energy is quenched, so that pairing is governed primarily by interactions and quantum geometry. We investigate characteristic superconducting length scales in all-flat-band systems…
A model of microscopic interaction between a superconductor and a one-dimensional topological insulator, an SSH chain, is considered. Using the functional integration method, the effective action of the interaction between a superconductor…
The superconductor/ferromagnet/superconductor (S/F/S) Josephson junctions (JJs) with an anomalous ground state phase shift $\varphi_0 \neq 0,\pi$ ($\varphi_0$-S/F/S JJs) enable the implementation of the zero-field Josephson diode effect…
Recent experiments engineered special spin-degenerate Andreev bound states in atomic cages of adatoms on superconductors, the Machida-Shibata states, a promising building block for quantum matter. Here, we investigate the formation of…
We theoretically investigate the anomalous and diode Josephson effects in planar two-dimensional Josephson junctions with arbitrarily oriented exchange fields in two ferromagnets within the barrier, and spin-orbit coupling at the…