Catalytic entanglement transformations with noisy hardware

TL;DR

This paper extends catalytic entanglement concentration to mixed states, benchmarks it under realistic noise, and introduces a new method for optimizing the required measurements, showing advantages under low-noise conditions.

Contribution

It introduces a novel recipe for determining POVMs in catalytic entanglement concentration, enabling tradeoffs and improved performance analysis under noisy hardware.

Findings

Catalytic EC outperforms distillation and non-catalytic EC under low noise.

The new recipe allows balancing communication rounds and auxiliary qubits.

Catalytic EC shows better rates in the presence of operational errors and depolarising noise.

Abstract

The availability of certain entangled resource states (catalyst states) can enhance the rate of converting several less entangled states into fewer highly entangled states in a process known as catalytic entanglement concentration (EC). Here, we extend catalytic EC from pure states to mixed states and numerically benchmark it against non-catalytic EC and distillation in the presence of state-preparation errors and operational errors. Furthermore, we analyse the re-usability of catalysts in the presence of such errors. To do this, we introduce a novel recipe for determining the positive-operator valued measurements (POVM) required for EC transformations, which allows for making tradeoffs between the number of communication rounds and the number of auxiliary qubits required. We find that in the presence of low operational errors and depolarising noise, catalytic EC can provide better rates than distillation and non-catalytic EC.