10 papers
Sample-Optimal Quantum Estimators for Pure-State Trace Distance and Fidelity via Samplizer
Qisheng Wang, Zhicheng Zhang
We settle the problem of estimating the trace distance and (square root) fidelity between -qubit pure quantum states to within additive error , given their independ…
Quantum Data Structure for Range Minimum Query
Qisheng Wang, Zhean Xu, Zhicheng Zhang
Given an array , the Range Minimum Query (RMQ) problem is to maintain a data structure that supports RMQ queries: given a range , find the index of the minimum ele…
A List of Complexity Bounds for Property Testing by Quantum Sample-to-Query Lifting
Kean Chen, Qisheng Wang, Zhicheng Zhang
Quantum sample-to-query lifting, a relation between quantum sample complexity and quantum query complexity presented in Wang and Zhang (SIAM J. Comput. 2025), was significantly str…
Time-Efficient Quantum Entropy Estimator via Samplizer
Qisheng Wang, Zhicheng Zhang
Entropy is a measure of the randomness of a system. Estimating the entropy of a quantum state is a basic problem in quantum information. In this paper, we introduce a time-efficien…
Quantum Lower Bounds by Sample-to-Query Lifting
Qisheng Wang, Zhicheng Zhang
The polynomial method by Beals, Buhrman, Cleve, Mosca, and de Wolf (FOCS 1998, J. ACM 2001), the adversary method by Ambainis (STOC 2000, J. Comput. Syst. Sci. 2002), and the compr…
Access Control Threatened by Quantum Entanglement
Zhicheng Zhang, Mingsheng Ying
Access control is a cornerstone of computer security that prevents unauthorised access to resources. In this paper, we study access control in quantum computer systems. We present…