Reconfigurable generation and measurement of mutually unbiased bases for time-bin qudits

TL;DR

This paper introduces a practical method for generating and measuring mutually unbiased bases in high-dimensional time-bin qudits using electro-optic modulators and fiber gratings, enabling scalable quantum information processing.

Contribution

It presents a novel, experimentally feasible approach for mutually unbiased basis generation in time-bin qudits, compatible with current technology and capable of rapid basis switching.

Findings

Successfully implements all $d+1$ mutually unbiased bases for $d=2,3,4$.

Analyzes the approach's performance in quantum key distribution scenarios.

Demonstrates practicality and scalability for high-dimensional quantum states.

Abstract

We propose a new method for implementing mutually unbiased generation and measurement of time-bin qudits using a cascade of electro-optic phase modulator -- coded fiber Bragg grating pairs. Our approach requires only a single spatial mode and can switch rapidly between basis choices. We obtain explicit solutions for dimensions $d=2,3,4$ that realize all $d+1$ possible mutually unbiased bases and analyze the performance of our approach in quantum key distribution. Given its practicality and compatibility with current technology, our approach provides a promising springboard for scalable processing of high-dimensional time-bin states.