In materials science, two-dimensional electron systems (2DES) realized at the oxide surface or interface are a promising candidate to achieve novel physical properties and functionalities in a rapidly emerging quantum field. While 2-DES provides an important platform for exotic quantum events including the quantum Hall effect and superconductivity, the effect of symmetry breaking ; transition from a disorderly state in to a more definite state, on such quantum phases remain elusive. Nonreciprocal electrical transport or current-direction-dependent resistance is a probe for broken inversion symmetry (presence of a dipole), as observed on several noncentrosymmetric crystals and interfaces. In a new report, Yuki M. Itahashi and a team of scientists in applied physics, nanosystems and materials science in Japan and the U.S. reported nonreciprocal transport at the surface of a 2-D superconductor made of the superconducting material strontium titanate (SrTiO3). The team observed gigantic enhancement of the nonreciprocal region in the superconducting fluctuation region—at six orders of magnitude larger compared to its normal state. The results are now published on Science Advances and demonstrate unprecedented characteristics of the 2-D polar superconductor.
Click here for original story, Nonreciprocal transport in the gate-induced strontium titanate polar superconductor
Source: Phys.org