Quantum cooling

15 May 2015

Dr Yung Man Hong, 2004 Croucher scholar and 2009 fellow, is an expert in quantum cooling.

The study of fundamental physical phenomena at low temperatures requires efficient cooling methods. As numerical tools, cooling algorithms are crucial for studying ground-state problems in computational physics, and for solving complex optimisation problems in computer science. Recent advances in quantum information science point open new avenues for scientific discovery in physics and chemistry. However, simulating low-temperature properties of many-body systems continues to be a challenging problem.

In secondary school, Yung developed an interest in science “Back at that time, I felt it was science that can give me a definite answer when I got confused. Physics aroused my curiosity and I wanted to explore more in this field.”

After graduating from the Chinese University of Hong Kong with a first-class honours degree, Yung was awarded a Croucher Scholarship to study for a PhD with Professor Anthony J Leggett, Nobel laureate in physics in 2003, at University of Illinois at Urbana-Champaign. It was under Leggett’s supervision that Yung increased his horizon and began concentrated on quantum simulation. He was awarded the Drickamer Research Fellowship in 2008 for having demonstrating significant ability in research.

In 2009 Yung was awarded a Croucher Fellowship and started working with professor Alán Aspuru-Guzik at Harvard University as a postdoctoral researcher. He had several publications during those years including A quantum-quantum Metropolis algorithm in 2012 in PNAS. He introduced a quantum version of the method of Markov-chain quantization combined with the quantum simulated annealing (QSA) procedure, and described explicitly a novel quantum Metropolis algorithm, which exhibits a quadratic quantum speedup in the eigenvalue gap of the corresponding Metropolis Markov chain for any quantum Hamiltonian. This result provided a complete generalization of the classical Metropolis method to the quantum domain.

Yung started to work on research problems in quantum information science, a highly interdisciplinary and emerging rapidly as a new field of science. In the 2014 his co-authored paper Demon-like Algorithmic Quantum Cooling and its Realization with Quantum Optics was published in Nature Photonics, Dr Yung and his coworkers generalized the idea of Maxwell’s Demon to the quantum domain. They found that given any quantum state, a quantum circuit can be applied such that the state is in a superposition of a hotter state and a colder state, relative to a Hamiltonian that can be simulated by a quantum computer. Projective measurement can be performed to obtain either of them probabilistically, in a way similar to that of Maxwell’s Demon.

Yung joined Tsinghua University in 2013 and has since been a tenure-track assistant professor at the Institute for Interdisciplinary Information Sciences. He teaches both undergraduate and graduate students, and advises two PhD students. “The students at Tsinghua are extremely talented and curious. Many of them were winners of science competitions in their high school years. I am pleased to have the chance to teach these young talents and I hope to help them make remarkable achievements in physical and computer sciences.” he said.

Yung arrived at Tsinghua as a young scientist of China’s Thousand Talents Plan, a government-sponsored recruitment programme of global experts. “The Institute for Interdisciplinary Information Sciences at Tsinghua University is highly international and collaborative. I have colleagues from all over the world and am fortunate to launch my career here.” he said.

Yung lives in Beijing with his family. In his leisure time, he enjoys cooking different types of food for the family.

To view Yung Man Hong's personal Croucher profile, please click here