arXiv subjects

Florian Pallier

Publications and source records attributed to Florian Pallier.

3 recordsLinked to original sources

arXiv2026

The electric-field-driven intermediate state of three-dimensional superconductors

The coexistence of superconductivity and finite electric fields may enable access to intriguing forms of electronic states. We demonstrate the emergence of an intermediate state in which electric fields penetrate the system while superconductivity still persists. Our measurements reveal a nonclassical regime characterized by the simultaneous presence of supercurrent and dissipative charge transport. This state, realized in a pristine unpatterned three-dimensional system, arises from electric-field-driven order parameter fluctuations. It provides a platform to explore dissipative states of charged quantum fluids far from equilibrium.

cond-mat.supr-con↗

arXiv2024

Transverse resistance due to electronic inhomogeneities in superconductors

Phase transitions in many-body systems are often associated with the emergence of spatial inhomogeneities. Such features may develop at microscopic lengthscales and are not necessarily evident in measurements of macroscopic quantities. In this work, we address the topic of distribution of current paths in superconducting films. Typical lengthscales associated with superconductivity are in the range of nanometres. Accordingly, measurements of electrical resistance over much larger distances are supposed to be insensitive to details of spatial inhomogeneities of electronic properties. We observe that, contrary to expectations, current paths adopt a highly non-uniform distribution at the onset of the superconducting transition which is manifested in the development of a finite transverse resistance. The anisotropic distribution of current density is unrelated to the structural properties of the superconducting films, and indicates the emergence of electronic inhomogeneities perceivable over macroscopic distances. Our experiments reveal the ubiquitous nature of this phenomenon in conventional superconductors.

cond-mat.supr-con↗

arXiv2023

Spontaneous voltage peaks in superconducting Nb channels without engineered asymmetry

Rectification effects in solid-state devices are a consequence of nonreciprocal transport properties. This phenomenon is usually observed in systems with broken inversion symmetry. In most instances, nonreciprocal transport arises in the presence of an applied magnetic field and the rectified signal has an antisymmetric dependence on the field. We have observed rectification of environmental electromagnetic fluctuations in plain Nb channels without any asymmetry in design, leading to spontaneous voltage peaks at the superconducting transition. The signal is symmetric in the magnetic field and appears even without an applied field at the critical temperature. This is indicative of an unconventional mechanism of nonreciprocal transport resulting from a spontaneous breaking of inversion symmetry.

cond-mat.supr-con↗