Daochen Wang
[last initial] [first name] at gmail dot com

I am an assistant professor of computer science at the University of British Columbia, where I research quantum computation and information.

Previously, I obtained my PhD from the University of Maryland under advisors Andrew Childs and Carl Miller. Before that, I obtained my BA and MMath from the University of Cambridge.

Name in Chinese: 王道辰.

I'm interested in the structures beneath quantum speed-ups, algorithm design, and real-world applications. I'm also interested in quantum cryptography. Works below are listed in order of first appearance on arXiv.

*: equal contribution
^†: alphabetical order, following convention in TCS

We study quantum graph algorithms given an edge list, making connections to fundamental questions in quantum query complexity.

We ground the security of the primary post-quantum digital signature scheme, standardized by NIST as ML-DSA, in the hardness of Module-LWE and Module-SIS.

We prove some special cases of a thirty-year-old conjecture from the analysis of Boolean functions, which has connections to post-selected quantum query complexity.

We prove that quantum algorithms generally work best when simulating quantum dynamics but can sometimes be fast-forwarded when simulating non-quantum dynamics.

We give a simpler proof-of-quantumness based on LWE and sketch applications to randomness generation, quantum money, and encrypted quantum simulation.

We quantumly speed up divide and conquer in certain settings and apply it to string problems, including longest increasing subsequence and longest common subsequence.

We show how to efficiently self-test the preparation and measurement of multiple EPR pairs assuming LWE cannot be solved quickly by quantum computers. Applications include device-independent quantum key distribution and dimension testing.

We quantify the quantum speedups achievable for reinforcement learning in terms of calls to a generative model of the underlying Markov decision process.

We construct an optimal quantum algorithm for identifying the best arm in a multi-armed bandit that is quadratically faster than any classical algorithm.

We characterise how a problem's symmetries determine whether quantum computation can drastically speed up its solution; it turns out that graph symmetries play the key role.

We reduce the number of measurements needed to estimate the expectation value of an observable by a few orders of magnitude via simultaneous measurements.

I extract a notion of "p-simulation" from a breakthrough paper in 2018 and then construct explicit classical circuits that can p-simulate any quantum circuit.

We enable the variational quantum eigensolver to compute excited states at little extra cost by penalising overlaps between quantum states. Integrated into IBM Qiskit.

We accelerate the variational quantum eigensolver by making it behave more like quantum phase estimation as more coherence time becomes available.

We find that super-short yet super-intense pulses of light can drive Rabi oscillations between bound states of negative energy and a pseudo-bound state of positive energy.

2024 W1: Quantum Computation: CPSC 436Q (undergraduate)
2023 W2: Topics in Quantum Computation: CPSC 536W (graduate)

Xingyu Zhou (PhD student)
Rain Zimin Yang (undergrad)

This is my PhD thesis, which I defended in Spring 2023.

Solutions to assignment problems from lecture course CS766/QIC820 Theory of Quantum Information (Fall 2017) at Waterloo by John Watrous. These problems also appear in the book on the left.

I contributed code that allows you to automatically retrieve molecular geometries from the PubChem database - try: geometry_from_pubchem('water').

Eureka is a recreational math magazine published by The Archimedeans society. This issue was published when I was the society's president a long time ago. Enjoy!

Last updated: 2nd July 2025
From Jon Barron