相关论文: Dissipation due to bulk localized low-energy modes…
The in-plane and out-of-plane surface impedance and microwave conductivity components of one and the same YBa_2Cu_3O_{7-x} (0.07\le x\le 0.47) single crystal are determined in the wide ranges of temperature T and carrier concentration p in…
We investigate electron transport and phase-breaking processes in thin titanium nitride (TiN) films of epitaxial quality. Previous studies show that a minute surface magnetic disorder significantly reduces the critical temperature…
To probe the influence of structural disorder on low-temperature behavior of magnetic penetration depth in electron-doped high-T_C superconductors, a comparative study of high-quality Pr_{1.85}Ce_{0.15}CuO_4 (PCCO) and…
High-Tc superconducting materials (HTSC) have anomalous properties such as the pseudo-gap or spin-gap etc., in Hall coefficient, 1/T1T and the density of states etc. First including effects of strong on-site repulsion between d-electrons at…
I report a theoretical study of collective coherent quantum-mechanical oscillations in disordered superconducting quantum metamaterials (SQMs), i.e artificially fabricated arrays of interacting qubits (two-levels system). An unavoidable…
Superconducting coplanar waveguide (SCPW) resonators have a wide range of applications due to the combination of their planar geometry and high quality factors relative to normal metals. However, their performance is sensitive to both the…
We develop a temperature dependent empirical pseudopotential theory to study the electronic and optical properties of self-assembled quantum dots (QDs) at finite temperature. The theory takes the effects of both lattice expansion and…
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…
Superconducting granular aluminum is attracting increasing interest due to its high kinetic inductance and low dissipation, favoring its use in kinetic inductance particle detectors, superconducting resonators or quantum bits. We perform…
Motivated by the recent optical conductivity experiments on Bi_2Sr_2CaCu_2O_{8+delta} films, we examine the possible origin of low-frequency dissipation in the superconducting state. In the presence of spatial inhomogeneity of the local…
This thesis studies three kinds of mesoscopic systems and how one of their collective degrees of freedom is affected by a dissipative environment: a)Nanoelectromechanical systems based on semiconductor materials, and how surface friction…
We investigate the microwave absorption arising from inhomogeneity in the superfluid density of a model high-T_c superconductor. Such inhomogeneities may arise from a wide variety of sources, including quenched random disorder and static…
We model s- and d-wave ceramic superconductors with a three-dimensional lattice of randomly distributed Josephson junctions with finite self-inductance. The field and temperature dependences of the microwave absoption are obtained by…
Phonon softening is a ubiquitous phenomenon in condensed matter systems which is often associated with charge density wave (CDW) instabilities and anharmonicity. The interplay between phonon softening, CDW and superconductivity is a topic…
Recent years have seen a resurgence of interest in multimode fibers due to their intriguing physics and applications, with spatial beam self-cleaning (BSC) having received special attention. In BSC light condenses into the fundamental fiber…
We have found a new mean field solution in the BCS theory of superconductivity. This unconventional solution indicates the existence of superconducting phase transitions of third order in thin films, or in bulk matter with a layered…
The attenuation of longitudinal ultrasonic wave with the frequency of 30 MHz in Cu-Nb copper-niobium (40 vol%) composite system at low temperatures from 0.35 K up to 2 K is researched. It was found that the ultrasonic attenuation decreases…
We argue that the standard Abrikosov-Gorkov (AG) type theory of $T_c$ in disordered $d$-wave superconductors breaks down in short coherence length high-$T_c$ cuprates. Numerical calculations within the Bogoliubov-de Gennes formalism…
The interplay of different emergent phenomena -- superconductivity (SC) and domain formation -- appearing on different spatial and energy scales are investigated using high-resolution scanning tunneling spectroscopy (STS) in the…
Periodic spatial modulations of the superfluid density, or pair density waves, have now been widely detected in unconventional superconductors, either as the primary or the secondary states accompanying charge density waves. Understanding…