$\mathcal{PT}$ phase control in circular multicore fibers

TL;DR

This paper demonstrates how geometric twisting of a circular multicore fiber with balanced gain and loss can control the transition between unbroken and broken $ ext{PT}$ phases, affecting optical transmission.

Contribution

It introduces a novel method of controlling $ ext{PT}$ phase transitions in multicore fibers through geometric twist, acting as an artificial gauge field.

Findings

Twist induces Peierls' phases in coupling constants.

Control of $ ext{PT}$ phases via fiber twist.

Tuning of optical transmission in six-core fiber.

Abstract

We consider light dynamics in a circular multicore fiber with balanced gain and loss core distribution, and show that transition from unbroken to broken $\mathcal{PT}$ phases can be conveniently controlled by geometric twist of the fiber. The twist introduces Peierls' phases in the coupling constants and thus acts as an artificial gauge field. As an application, we discuss twist-induced tuning of optical transmission in a six-core fiber with one lossy core.