Related papers: Quantum fluctuations and phase coherence in superc…
At temperatures $T < {\hbar v_F}/{K_B d} \equiv T^{wire}$ the collective excitations are negligible and the spectrum of the short wire is dominated by the ''zero modes'' particle excitations. At temperature $ T > T^{wire}$ a spin polarized…
We discuss the scenario of superconducing transition for quasi two dimension HTS with spin fluctuation pairing mechanism. At mean field temperature of 2D superconducting transition the interaction of fluctuation spin waves with holes in…
Systems with itinerant fermions close to a zero temperature quantum phase transition like the high temperature superconductors exhibit unusual non-Fermi liquid properties. The interaction of the long-range and low-energy fluctuations of the…
Based on calculations using the local density approximation, we propose quantum wire networks with square and plaquette type lattice structures that form quantum dot superlattices. These artificial structures are well described by the…
An important question in the physics of superconducting nanostructures is the role of thermal fluctuations on superconductivity in the zero-dimensional limit. Here, we probe the evolution of superconductivity as a function of temperature…
Evidence of a non-thermal magnetic relaxation in the intermediate state of a type-I superconducor is presented. It is attributed to quantum tunneling of interfaces separating normal and superconducting regions. Tunneling barriers are…
Quantum phase transitions typically result in a broadened critical or crossover region at nonzero temperature. Josephson arrays are a model of this phenomenon, exhibiting a superconductor-insulator transition at a critical wave impedance,…
Temporal fluctuations in the superconducting qubit lifetime, $T_1$, bring up additional challenges in building a fault-tolerant quantum computer. While the exact mechanisms remain unclear, $T_1$ fluctuations are generally attributed to the…
Quantum phase slip (QPS) is the particular manifestation of quantum fluctuations of the order parameter of a current-biased quasi-1D superconductor. The QPS event(s) can be considered a dynamic equivalent of tunneling through conventional…
We have observed reproducible conductance fluctuations at low temperature in a small GaAs:Si wire driven across the Anderson transition by the application of a gate voltage. We analyse quantitatively the log-normal conductance statistics in…
We study the transport properties of ultrathin disordered nanowires in the neighborhood of the superconductor-metal quantum phase transition. To this end we combine numerical calculations with analytical strong-disorder renormalization…
Quantum phase transitions are sudden changes in the ground-state wavefunction of a many-body system that can occur as a control parameter such as a concentration or a field strength is varied. They are driven purely by the competition…
We consider the effect of classical phase fluctuations on the quasiparticle spectra of underdoped high-$T_c$ cuprate superconductors in the pseudogap regime above $T_c$. We show that photoemission and tunneling spectroscopy data are well…
Dimensionality of a physical system, conventionally an invariant geometric characteristic, fundamentally governs the universality class of phase transitions and the landscape of emergent collective phenomena. In low-dimensional or layered…
In superconductors where the coherence length is comparable to the Fermi wavelength, the electronic levels within a vortex core are quantized, and separated by energies of the order of the superconducting gap. The absence of a continuum…
Quantum conductance of 3D ballistic wires with idealy flat boundaries obeys fluctuations with the properties quite distinguishable from those of universal conductance fluctuations: Both their amplitude and the sensitivity to the magnetic…
We present the results from an experimental study of the magneto-transport of superconducting wires of amorphous Indium-Oxide, having widths in the range 40 - 120 nm. We find that, below the superconducting transition temperature, the wires…
Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation…
For a system at a temperature of absolute zero, all thermal fluctuations are frozen out, while quantum fluctuations prevail. These microscopic quantum fluctuations can induce a macroscopic phase transition in the ground state of a many-body…
When a second-order magnetic phase transition is tuned to zero temperature by a non-thermal parameter, quantum fluctuations are critically enhanced, often leading to the emergence of unconventional superconductivity. In these `quantum…