Papers accepted by PRL!

Paper on quantum channel simulation have been accepted by PRL 🎉

Our papers Shadow Simulation of Quantum Processes by Xuanqiang Zhao, Xin Wang and Giulio Chiribella have been accepted by PRL. This work is completed in collaboration with Prof. Chiribella and his PhD student Xuanqiang from the Quantum Information and Computation Initiative at The University of Hong Kong, Department of Computer Science.

For PRL: Physical Review Letters (PRL) is the world's premier physics letter journal and the American Physical Society's flagship publication. Since 1958 it has contributed to APS's mission to advance and diffuse the knowledge of physics by publishing seminal research by Nobel Prize–winning and other distinguished researchers in all fields of physics.

For the paper Shadow Simulation of Quantum Processes: In this work, we introduce a new quantum information processing task called shadow process simulation, where the goal is to reproduce the expectation values of all possible observables at the output of a target quantum channel. Shadow process simulation generalizes quantum channel simulation, a fundamental primitive in quantum information theory, and offers a unified framework for a range of recently proposed quantum protocols, including error mitigation and circuit knitting. We find that shadow process simulation generally can surpass the limits of conventional protocols in quantum communication and channel formation, albeit with an increased measurement overhead. Surprisingly, we also find that shadow simulation can achieve a more precise approximation of several types of quantum channels without incurring any measurement overhead.

On the foundational level, our work sheds light on the interpretation of a quantum state, which is commonly viewed as an encoding of the expectation values of arbitrary observables. Our results show that transferring an encoding of all expectation values is a much less demanding task than transmitting the quantum state itself, suggesting that the quantum state is more than just a catalogue of expectation values. On the practical level, our work provides new efficient methods for measuring observables with noisy quantum devices, as well as new communication protocols for transmitting multiple complementary pieces of information.