Related papers: Conductance fluctuations near Anderson transition
Polycrystalline Sr1-xNdxFeAsF samples were prepared at various Nd-doping levels using both a stoichiometric mixture of the starting materials and in slight excess amounts of FeAs. Susceptibility and resistivity of the samples were studied…
Fluctuations of conserved quantities within a subsystem are non-local observables that provide unique insights into quantum many-body systems. In this paper, we study bipartite charge (and spin) fluctuations across interaction-driven…
By direct application of the fluctuation-dissipation theorem, we numerically calculate the fundamental dimensional fluctuations of crystalline CaF2 whispering gallery resonators in the case of structural damping, and the limit that this…
We use a random gap model to describe a metal-insulator transition in three-dimensional semiconductors due to doping and find a conventional phase transition, where the effective scattering rate is the order parameter. Spontaneous symmetry…
At low energy scales charge transport in the insulating Si:P is dominated by activated hopping between the localized donor electron states. Thus, theoretical models for a disordered system with electron-electron interaction are appropriate…
We show that 1/f noise in a two-dimensional electron gas with hopping conduction can be explained by the modulation of conducting paths by fluctuating occupancy of non-conducting states. The noise is sensitive to the structure of the…
We report a theoretical investigation on conductance fluctuation of mesoscopic systems. Extensive numerical simulations on quasi-one dimensional, two dimensional, and quantum dot systems with different symmetries (COE, CUE, and CSE)…
Resistance noise spectroscopy is applied to bulk single crystals of the quasi-two-dimensional organic Mott insulator $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl both under moderate pressure and at ambient-pressure conditions. When pressurized,…
In order to investigate the origin of the until now unaccounted excess noise and to minimize the uncontrollable phenomena at the transition in X-ray microcalorimeters we have developed superconducting transition-edge sensors into an…
We present low-temperature measurements of the low-frequency $1/f$ noise arising from an ensemble of two-level fluctuators in the oxide barrier of Al/AlO$_{x}$/Al Josephson junctions. The fractional noise power spectrum of the…
Using uniaxial stress to tune Si:B through the metal-insulator transition we find the conductivity at low temperatures shows an excellent fit to scaling with temperature and stress on both sides of the transition. The scaling functions…
Magnetic field dependent universal conductance fluctuations (UCF's) are observed in weakly disordered indium tin oxide nanowires from 0.26 K up to $\sim 25$ K. The fluctuation magnitudes increase with decreasing temperature, reaching a…
VO2 features concomitant structural and metal-insulator transitions. This poses a challenge for understanding the underlying mechanism: is the transition triggered by a structural or by an electronic instability? The two scenarios are…
If the topological insulator Bi$_{2}$Se$_{3}$ is doped with electrons, superconductivity with $T_{{\rm c}}\approx3-4\:{\rm K}$ emerges for a low density of carriers ($n\approx10^{20}{\rm cm}^{-3}$) and with a small ratio of the…
We study the effect of a single bistable scatterer on conductance of mesoscopic conductors in the crossover regime from open to closed systems. After the resistance of the contact between the metallic grain and bulk electrode exceeds the…
Resistivity measurements were carried out up to 8 GPa on single crystal and polycrystalline samples of CeCu2Si2 from differing sources in the homogeneity range. The anisotropic response to current direction and small uniaxial stresses was…
We report comprehensive pair distribution function measurements of the hole-doped iron-based superconductor system Sr$_{1-x}$Na$_{x}$Fe$_2$As$_2$. Structural refinements performed as a function of temperature and length scale reveal…
We propose here an experiment aimed to determine whether there are superconducting pairing fluctuations in the pseudogap regime of the high-$T_c$ materials. In the experimental setup, two samples above $T_c$ are brought into contact at a…
Due to presence of magnetic field gradient needed for coherent spin control, dephasing of single-electron spin qubits in silicon quantum dots is often dominated by $1/f$ charge noise. We investigate theoretically fluctuations of ground…
Spin fluctuations enter the calculation of the superconducting transition temperature T$_c$ only in the next-to-leading order (i.e., in O(1/N$^2$) of the 1/N expansion of the t-J model. We have calculated these terms and show that they have…