Related papers: Superconducting phase transitions in disordered Nb…
In many classes of unconventional superconductors, the question of whether the superconductivity is enhanced by the quantum-critical fluctuations on the verge of an ordered phase remains elusive. One of the most direct ways of addressing…
The magnetic-field-tuned quantum superconductor-insulator transitions of disordered amorphous indium oxide films are a paradigm in the study of quantum phase transitions, and exhibit power-law scaling behavior. For superconducting indium…
The development of large-scale quantum processors benefits from superconducting qubits that can operate at elevated temperatures and be fabricated with scalable, foundry-compatible processes. Atomic layer deposition (ALD) is increasingly…
We present measurements of $ab$-plane resistivity $\rho_{ab}(T)$ and superfluid density [$\propto \lambda^{-2}$, $\lambda$ = magnetic penetration depth] in $La_{2-x}Sr_{x}CuO_{4}$ films. As Sr concentration $x$ exceeds about 0.22, the…
Superconductivity arises from the global phase coherence of Cooper pairs. Modulation of phase coherence leads to quantum phase transitions, serving as an important tool for studying unconventional superconductivity. Here, we demonstrate…
The discovery of superconductivity under high pressure in Ruddlesden-Popper phases of bulk nickelates has sparked great interest in stabilizing ambient pressure superconductivity in thin-film form using epitaxial strain. Recently, signs of…
A variety of nickel oxide compounds have long been studied for their manifestation of various correlated electron phenomena. Recently, superconductivity was observed in nanoscale infinite layer nickelate thin films of…
Unconventional superconductivity typically emerges out of a strongly correlated normal state, manifesting as a highly renormalized Fermi liquid or a strange metal with $T$-linear resistivity. In Ruddlesden-Popper bilayer nickelates,…
The newly found superconductivity in infinite-layer nickelate superconducting films has attracted much attention, because their crystalline and electronic structures are similar to high-$T_c$ cuprate superconductors. The upper critical…
We measure the frequency dependence of the complex ac conductivity of NbN films with different levels of disorder in frequency range 0.4-20 GHz. Films with low disorder exhibit a narrow dynamic fluctuation regime above T_c as expected for a…
The mechanism through which superconductivity is destroyed upon controlled disordering often holds the key to understanding the mechanism of emergence of superconductivity. Here we demonstrate an $in$-$situ$ mechanism to control the…
Among the recognized sources of decoherence in superconducting qubits, the spatial inhomogeneity of the superconducting state and the possible presence of magnetic-flux vortices remain comparatively underexplored. Niobium is commonly used…
Nickel-based complex oxides have served as a playground for decades in the quest for a copper-oxide analog of the high-temperature superconductivity. They may provide clues towards understanding the mechanism and an alternative route for…
The pairing symmetry of superconducting infinite-layer nickelates is a fundamental yet experimentally challenging question. We employ high-energy electron irradiation to induce disorder in superconducting Nd$_{0.825}$Sr$_{0.175}$NiO$_2$…
We present the electrical transport characteristics of a batch of nano-crystalline diamond films of varying nitrogen concentrations and explain the conduction mechanism by the disordered quasi-superlattice model applied to semiconductor…
Epitaxial bilayer films of Bi(110) and Ni host a time-reversal symmetry (TRS) breaking superconducting order with an unexpectedly high transition temperature $T_c = 4.1$ K. Using time-domain THz spectroscopy, we measure the low energy…
Superconducting Nb thin films with rectangular arrays of submicron antidots have been systemically investigated by transport measurements. In low fields, the magnetoresistance curves demonstrate well-defined dips at integral and rational…
All non-interacting two-dimensional electronic systems are expected to exhibit an insulating ground state. This conspicuous absence of the metallic phase has been challenged only in the case of low-disorder, low density, semiconducting…
We have studied the thickness-induced superconductor-to-insulator transition in the presence of a magnetic field for a-NbSi thin films. Analyzing the critical behavior of this system within the "dirty boson model", we have found a critical…
We present a comprehensive study of how superconducting fluctuations in the normal state contribute to the conductivity tensor in a thin (119 $\AA$) film of NbN. It is shown how these fluctuations drive a sign change in the Hall coefficient…