Research

Funding/Proposal Experience

Research Highlights

[J27] J. P. Zhan. Near-perfect Reachability of Variational Quantum Search with Depth-1 Ansatz, arXiv:2301.13224, Jan. 2023 [https://arxiv.org/abs/2301.13224]  

Highlight: We show that the exponentially deep circuit required by Grover’s algorithm can be replaced by a multi-controlled NOT gate together with a single layer of Ry gates. We prove that the Variational Quantum Search, with a single layer of Ry gates as its Ansatz, has near-perfect reachability in finding the good element of an arbitrarily large unstructured data set, and its reachability exponentially improves with the number of qubits.

[J26] J. P. Zhan. Quantum Feasibility Labeling for NP-complete Vertex Coloring Problem, arXiv:2301.01589, Jan. 2023 [https://arxiv.org/abs/2301.01589]

Highlight: The Quantum Feasibility Labeling algorithm, together with our Variational Quantum Algortihm, could be the first algorithm to solve an NP-complete problem in polynomial time, provided that the VQS is proved to be efficient for any number of qubits. The figure shows the quantum circuit for the Quantum Feasibility Labeling algorithm, where FLQ is short for feasibility label qubit. 

[J25] J. P. Zhan. Variational Quantum Search with Exponential Speedup, arXiv:2212.09505, Dec. 2022 [https://arxiv.org/abs/2212.09505]

Highlight: The figure demonstrates that the circuit depth of VQS and Grover’s algorithm increases linearly and exponentially, respectively. That is, VQS achieves an exponential advantage over Grover’s algorithm in terms of circuit depth. We envisage our VQS could exponentially speed up the solutions to many important problems, including the NP-complete problems, which is widely considered impossible. 

Research

As a Postdoctoral Fellow at the University of Saskatchewan

As a Postdoctoral Fellow at The Hong Kong Polytechnic University

As a Visiting Research Assistant at the South China University of Technology

As a Visiting Research Assistant at the University of Liverpool

As a Ph.D. and undergraduate student at the Zhejiang University