Indefinite causal order for quantum phase estimation with Pauli noise

Abstract

This letter further explores the recent scheme of switched quantum channels with indefinite causal order applied to the reference metrological task of quantum phase estimation in the presence of noise. We especially extend the explorations, previously reported with depolarizing noise and thermal noise, to the class of Pauli noises, important to the qubit and not previously addressed. Nonstandard capabilities, not accessible with standard quantum phase estimation, are exhibited and analyzed, with significant properties that are specific to the Pauli noises, while other properties are found in common with the depolarizing noise or the thermal noise. The results show that the presence and the type of quantum noise are both crucial to the determination of the nonstandard capabilities from the switched channel with indefinite causal order, with a constructive action of noise reminiscent of stochastic resonance phenomena. The study contributes to a more comprehensive and systematic characterization of the roles and specificities of quantum noise in the operation of the novel devices of switched quantum channels with indefinite causal order.

arXiv comment8 pages, 2 figures, 22 references

References in corpus (12)

• Quantum correlations with no causal order
• Quantum computations without definite causal structure
• Using entanglement against noise in quantum metrology
• Experimental Superposition of Orders of Quantum Gates
• Enhanced communication with the assistance of indefinite causal order
• Indefinite Causal Order in a Quantum Switch
• Experimental transmission of quantum information using a superposition of causal orders
• Communication Enhancement Through Quantum Coherent Control of $N$ Channels in an Indefinite Causal-order Scenario
• Noisy quantum metrology with the assistance of indefinite causal order
• Indefinite causal order for quantum metrology with quantum thermal noise
• Stochastic resonance effects in quantum channels
• Modeling and simulation of a quantum thermal noise on the qubit

Cited by in corpus (3)

• Reassessing the advantage of indefinite causal orders for quantum metrology
• Using Quantum Switches to Mitigate Noise in Grover's Search Algorithm
• Correlations in a quantum switch-based heat engine with measurements: A proof-of-principle demonstration