Generation and Eight-port Homodyne Characterization of Time-bin Qubits for Continuous-variable Quantum Information Processing

TL;DR

This paper demonstrates the generation of arbitrary time-bin qubits compatible with continuous-variable quantum processing and introduces an efficient eight-port homodyne method for their complete characterization.

Contribution

It presents a novel method to generate and characterize time-bin qubits using continuous-wave light and eight-port homodyne measurement, enhancing integration with existing quantum technologies.

Findings

Successful generation of arbitrary time-bin qubits compatible with CV technology

Efficient eight-port homodyne scheme for full two-mode state characterization

Flexible analysis method equivalent to traditional interferometric schemes

Abstract

We experimentally generate arbitrary time-bin qubits using continuous-wave light. The advantage unique to our qubit is its compatibility with deterministic continuous-variable quantum information processing. This compatibility comes from its optical coherence with continuous waves, well-defined spatio-temporal mode, and frequency spectrum within the operational bandwidth of the current continuous-variable technology. We also demonstrate an efficient scheme to characterize time-bin qubits via eight-port homodyne measurement. This enables the complete characterization of the qubits as two-mode states, as well as a flexible analysis equivalent to the conventional scheme based on a Mach-Zehnder interferometer and photon-detection.