Showcasing the necessity of the principle of relative motion in physical statistics: Inconsistency of the `segmented Fermi surface'

Abstract

The hunt for exotic properties in flowing systems is a popular and active field of study, and has recently gained renewed attention through claims such as a ``segmented Fermi surface'' in a superconducting system that hosts steady superflow of screening current driven by an external field. Apart from this excitement and the promise of hosting Majorana zero modes, claims such as this imply exotic gap-to-gapless quantum phase transitions merely through boost of inertial frames of observation, and challenge the very concept behind the principle of relative motion. Here, we first illustrate an obvious inescapable physical inconsistency of such claims concerning the flow velocity. Taking into account this basic principle from the beginning, we then demonstrate that a proper employment of physical statistics naturally reproduces the experimental observation without causing such a conceptual crisis. This example showcases the importance of strict adherence to the basic principle of relative motion in physical statistics, especially when pushing the frontiers of physics and technology.