Superconductivity
Recently developed terahertz (THz) two-dimensional coherent spectroscopy (2DCS) is a powerful technique to obtain materials information in a fashion qualitatively different from other spectroscopies. Here, we utilized THz 2DCS to…
Conditions at which a quasi-one-dimensional (1D) electron system can be considered as a quantum liquid of impenetrable charged particles are theoretically analyzed. In the presence of an inert, neutralizing background, a motion of…
The robustness of the macroscopic quantum nature of a superconductor can be characterized by the superfluid stiffness, $\rho_s$, a quantity that describes the energy required to vary the phase of the macroscopic quantum wave function. In…
Nonadiabatic effects in the electron-phonon coupling are important whenever the ratio between the phononic and the electronic energy scales, the adiabatic ratio, is non negligible. For superconducting systems, this gives rise to additional…
In this work, the Ginzburg-Landau theory is represented on a symplectic manifold with a phase space content. The order parameter is defined by a quasi-probability amplitude, which gives rise to a quasi-probability distribution function,…
Superconducting diode effects (SDEs) occur in systems with asymmetric critical supercurrents $|I^c_+|\neq |I^c_-|$ yielding dissipationless flow in one direction $(e.g., +)$, while dissipative transport in the opposite direction $(-)$. Here…
In superconductors, the combination of broken time-reversal and broken inversion symmetries can result in a critical current being dependent on the direction of current flow. This phenomenon is known as superconducting diode effect (SDE)…
We demonstrate ion irradiation by argon or gallium as a wafer-scale post-processing method to increase disorder in superconducting thin films. We study several widely used superconductors, both single-elements and compounds. We show that…
The discovery of 80 K superconductivity in bilayer La$_3$Ni$_2$O$_7$ at pressures greater than 14 GPa presents a unique opportunity to study a novel class of high-temperature superconductors. Therefore, other bilayer nickelate following the…
In this study, we explore the Josephson current-phase relation within a planar diffuse tunneling superconducting multilayer junction subjected to a parallel magnetic field. Our investigation involves computing the supercurrent associated…
Polarization analyses of the terahertz (THz) emission from Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ whisker crystals used for superconducting THz emitters were conducted. The THz emission mode was estimated by a simple polarization…
We propose the superconducting van der Waals material 4Hb-TaS$_2$ to realize the $\mathbb{Z}_2$ topological order and interpret the recent discovery of the spontaneous vortex generation in 4Hb-TaS$_2$ as the vison-vortex nucleation. For the…
The clathrate-like or caged compounds have attracted continuing interest due to their structural flexibility as well as fertile physical properties. Here we report a pressure-induced reemergence of superconductivity in BaIr2Ge7 and…
We investigate the pinning mechanism in high-critical-current polycrystalline samples of Bi-2223 (Bi2Sr2Ca2Cu3O10) utilized in high current applications. Using differential magneto-optical (DMO) imaging technique, we track the magnetic…
We demonstrate a-axis YBa2Cu3O7-x/PrBa2Cu3O7-x/YBa2Cu3O7-x trilayers grown on (100) LaAlO3 substrates with improved interface smoothness. The trilayers are synthesized by ozone-assisted molecular-beam epitaxy. The thickness of the…
The microscopic doping mechanism behind the superconductor-to-insulator transition of a thin film of YBa2Cu3O7 was recently identified as due to the migration of O atoms from the CuO chains of the film. Here we employ density-functional…
Transition-Edge Sensors (TESs) are two-dimensional superconducting films used to detect energy or power. TESs are voltage biased in the resistive transition where the film resistance is both finite and a strong function of temperature.…
We present a study of thin-film molybdenum resistors for NbN electronics operating at cryogenic temperatures. The key step is the 0.5-1.5 keV ion cleaning-activation of NbN before Mo deposition which allows to obtain a high-quality Mo/NbN…
We study superconductor/normal region/superconductor (S|N|S) Josephson junction formed using superconductors with d, d + id', and d + is superconducting pairings. We show that the quality factor of the Josephson diode effect and its sign…
Manganese telluride (MnTe) has garnered strong interest recently for its antiferromagnetic semiconductor properties, which are promising for applications in spintronics, data storage, and quantum computing. In this study, we discovered that…