Quantum Channel Construction with Circuit Quantum Electrodynamics

TL;DR

This paper presents a universal, resource-efficient protocol for constructing any quantum channel using circuit quantum electrodynamics, enabling advanced quantum control and information processing.

Contribution

It introduces a novel, efficient method to realize all quantum channels with a single qubit ancilla and adaptive control, suitable for various physical platforms.

Findings

Protocol is implementable with superconducting circuits.

Construction is resource-efficient in circuit depth and physical resources.

Enables diverse applications like quantum error correction and quantum measurement.

Abstract

Quantum channels can describe all transformations allowed by quantum mechanics. We provide an explicit universal protocol to construct all possible quantum channels, using a single qubit ancilla with quantum non-demolition readout and adaptive control. Our construction is efficient in both physical resources and circuit depth, and can be demonstrated using superconducting circuits and various other physical platforms. There are many applications of quantum channel construction, including system stabilization and quantum error correction, Markovian and exotic channel simulation, implementation of generalized quantum measurements and more general quantum instruments. Efficient construction of arbitrary quantum channels opens up exciting new possibilities for quantum control, quantum sensing and information processing tasks.