Comment on ``Friedel phases and phases of transmission amplitudes in quantum scattering systems" by T. Taniguchi and M. Buettiker

TL;DR

This paper investigates how modifying boundary conditions in quantum scattering systems affects phase behavior, showing that continuous phase slips can still reveal the density of states, bridging idealized and realistic models.

Contribution

It introduces a tunable boundary condition approach to model phase slips in quantum scattering, connecting discontinuous and continuous phase behaviors.

Findings

Modified boundary conditions simulate transmission zeroes as minima.

Continuous phase slips still encode density of states information.

The approach bridges idealized and realistic quantum scattering models.

Abstract

We take a modified boundary condition at the dead end of a stub to simulate transmission zeroes being replaced by minima and then the discontinuous phase slip (or decrease) at the transmission zeroes are replaced by a continuous but rapid phase slip. The modified boundary condition can be continuously tuned to give the results of the stub with hard wall boundary condition at the dead end of stub. Even when the phase slip is continuous one can obtain information about the density of states in the stub region from the scattering phases.