First two physics papers with WQC address

The newly established Wilczek Quantum Center (WQC) is proud to announce that important papers from two different teams of researchers will appear in respected physics journal on advanced topics related to quantum computing. In each paper, the first author includes in his research address "Wilczek Quantum Center, Zhejiang University of Technology."

What is quantum computing? The theory of quantum computers (so far none exist) says that we can create a new generation of super-powerful computers if we control the quirky behavior of "quantum" matter. Not only universities but big companies around the world spend vast resources on this exciting topic. Such studies are a major focus at WQC.

Only a few weeks after the opening ceremonies at WQC, the respected New Journal of Physics published in its December 2014 issue the first paper to carry the address WQC. This peer-reviewed online journal, established in 1998, is published by London's Institute of Physics and the Deutsche Physikalische Gesellschaft. The three authors of "Hierarchical Theory of Quantum Adiabatic Evolution" are Qi Zhang of WQC and ZJUT, Jiangbing Gong of Singapore's National University, and Biao Wu of PKU and WQC. Qi Zhang, who is a professor at WQC/ZJUT, often takes part in the WQC hiking expeditions.

As co-author Biao Wu explained to WQC News, "One of the algorithms for quantum computer is the quantum adiabatic algorithm. Our theory should help people to find the quantum adiabatic algorithms which are faster and more accurate."

Wu adds, "In many physical systems, there are two types of motions, a fast motion and a slow motion. For example, in a hydrogen molecule, two protons move much slower than two electrons as protons are much more massive. It is then interesting to ask whether the slowly-moving protons can induce transition between different quantum energy states of the electrons. Physicists including Einstein and Ehrenfest began to ask this question at the very early stage of quantum theory. In 1928, Born and Fock answered this question in a rigorous way by proving the quantum adiabatic theorem. According this theorem, when the slow motion is infinitesimally small, there is no transition between quantum energy states of the fast motion. However, in reality, the slow motion is not infinitesimally small and has a finite small rate. This slow motion with finite rate will cause transition between quantum energy states of the fast motion. We try to find out how big or small this transition is."

The second paper to appear showing a WQC address also has two WQC coauthors, and has been accepted to Physical Review Letters (PRL), one of top world journals in physics. The paper "Weyl Superfluidity in a Three-dimensional Dipolar Fermi Gas" has four co-authors, two of whom (Bo Liu and Vincent Liu) mention their affiliation with WQC, as well as with the University of Pittsburgh.

Because quantum computers will depend on our ability to control quantum behavior, this paper presents an important advance from high energy particle physics concerning the "Weyl fermion." WQC Director Vincent Liu explains this as follows: "Weyl fermions carry exactly zero mass, so they travel in space with speed of light. Physicists call them right or left-handed because they spin either clockwise or anticlockwise (never in between) about the direction of traveling. For many decades, neutrinos were thought to be the most probable candidates until that idea was ruled out in recent years. High energy experiments actually discovered neutrinos are not exactly massless."

There has been a great hope among physicists to discover an actual Weyl fermion. In this PRL paper, Liu et al. propose a critical step for creating Weyl fermions in a low-energy non-relativistic quantum gas of magnetic dipoles. Somewhat poetically, Vincent Liu tells WQC News, "Much like a group of well- organized dancers, the atoms produce beautiful waves, moving in the Fermi speed, the equivalent of speed of light in an otherwise non-relativistic system. Much like the duality of optical waves and photons in quantum physics, those waves are Weyl particles."

WQC News would like to express thanks and gratitude to all authors of these two papers. While addressing the deepest problems of quantum computing, you have also shared the honor of your discoveries with WQC.

Hongwei Xiong, Biao Wu, and Vincent Liu at WQC opening ceremonies, October 2014

WQC opening ceremony, October 2014. Left to right: WQC Associate Director Hongwei (Henry) Xiong, Professor Biao (Bill) Wu of Peking University, and WQC Director Vincent Liu. Biao Wu is a coauthor of the first scholarly paper from WQC and Vincent Liu is a coauthor of the second.

First paper from WQC. WQC Professors Qi Zhang and Biao Wu are among the authors.

Quantum adiabatic computers are an important potential kind of quantum computer.

Qi Zhang hiking with other WQC members

Here is Qi Zhang, first author of the first paper from Wilczek Quantum Center, hiking near Hangzhou with other WQC members.

Weyl Fermion paper, accepted by Physical Review Letters

Weyl fermions are an intriguing type of quantum matter, predicted but not yet reliably observed. This paper describes a physical system where they might be seen and studied.

Coauthors of Weyl fermion paper, Bo Liu and Vincent Liu, in Pittsburgh

Two WQC coauthors of Weyl fermion paper pose against background of snowy Pittsburgh, PA, USA. Bo Liu (left) and Vincent Liu (right) are affiliated with both WQC and the University of Pittsburgh.