About me

I’m a Physics PhD candidate at Duke University, working as a theorist in Brown Lab. I finished my undergrad in Stanford University. I’m originally from South Korea.

I am excited about using quantum physics to build quantum computers/simulators, and using quantum computers/simulators to better understand the quantum Nature. My research interest is in quantum error correction, quantum simulation, and quantum control.

Debopriyo Biswas and I have been making a Youtube series Quantum News Monthly. We make 10-minute videos on exciting news and publications in the field of quantum physics and quantum computing each month, so check out if you’re interested!

Besides physics, I enjoy stand-up comedy and basketball.

Research Highlights

Quantum Simulation of Spin-Boson Models with Structured Bath

K. Sun, MK, H. Nuomin, G. Schwartz, D.N. Beratan, K.R. Brown, and J. Kim

arXiv:2405.14624 (2024)

We simulate the spin-boson model, a paradigmatic model of non-Markovian open quantum systems, using the motional modes of trapped ions. The dissipative behavior of the dynamics is captured by applying randomness to the control parameters.

Seeking a Quantum Advantage with Trapped-Ion Quantum Simulations of Condensed-Phase Chemical Dynamics

MK, H. Nuomin, S.N. Chowdhury, J.L. Yuly, K. Sun, J. Whitlow, J. Valdiviezo, Z. Zhang, P. Zhang, D.N. Beratan, K.R. Brown,

Nature Reviews Chemistry 8, 340-358 (2024) [arXiv:2305.03156]

Analog-quantum simulation derived from tracking the evolution of trapped-ion systems holds the potential to simulate molecular quantum dynamics that is beyond the reach of classical-digital strategies. This Review explores the prospects for developing this quantum advantage.

* Accepted talk at the 23rd Asian Quantum Information Science Conference (AQIS23), Seoul [Seminar]

Quantum Error Correction with Metastable States of Trapped Ions Using Erasure Conversion

MK, W.C. Campbell, and K.R. Brown

PRX Quantum 4, 020358 (2023) [arXiv:2210.15024]

Erasures, or errors with known locations, are more favorable than typical Pauli errors for quantum error correction. We suggest converting physical noise to erasures on trapped ions by using metastable atomic states as qubit states. Then we compare the error-correction performance of metastable and ground qubits under various physical constraints.

* Accepted talk at the 6th International Conference on Quantum Error Correction (QEC23), Sydney [Talk]

Designing Filter Functions of Frequency-Modulated Pulses for High-Fidelity Two-Qubit Gates in Ion Chains

MK, Y. Wang, C. Fang, B. Zhang, O. Khosravani, J. Kim, and K.R. Brown

Physical Review Applied 19, 014014 (2023) [arXiv:2206.10850]

We derive and design filter functions of the laser pulses for two-qubit gates on trapped ions, in order to suppress the effects of time-varying fluctuations of the motional-mode frequencies. This improves the experimentally measured gate fidelity from 99.23(7)% to 99.55(7)% in a five-ion chain.