Superconducting fluctuations at low temperature

Existence of anisotropic spin fluctuations at low temperature in the normal phase of the superconducting ferromagnet UCoGe

Thermal conductivity measurements have been performed on the superconducting ferromagnet UCoGe down to very low temperature and under magnetic field. In addition to the electronic quasiparticle thermal conductivity, additional contributions to the thermal transport are detected: they are sensitive to the amplitude and direction of the magnetic field and at low temperature, they display a strong...

Detecting temperature fluctuations at equilibrium.

The Gibbs and the Boltzmann definition of temperature agree only in the macroscopic limit. The ambiguity in identifying the equilibrium temperature of a finite-sized 'small' system exchanging energy with a bath is usually understood as a limitation of conventional statistical mechanics. We interpret this ambiguity as resulting from a stochastically fluctuating temperature coupled with the phase...

Low-temperature quantum fluctuations in overdamped ratchets.

At low temperatures and strong friction the time evolution of the density distribution in position follows a quantum Smoluchowski equation. Recently, also higher-order contributions of quantum fluctuations to drift and diffusion coefficients have been systematically derived. As a nontrivial situation to reveal the impact of subleading quantum corrections and to demonstrate convergence propertie...

Quantum Fluctuations in Superconducting Dots at Finite Temperatures

We study the thermodynamics of ultrasmall metallic grains with level spacing δ comparable or smaller than the pairing correlation energy, at finite temperatures, T> ∼ δ. We describe a method which allows to find quantum corrections to the effect of classical fluctuations. We present results for thermodynamic quantities in ordered grains and for the reentrant odd susceptibility in disordered gra...

Lyophilizing Foot-and Mouth Disease Virus at Low Drying Temperature