A bona fide topological Mott insulator discovered in twisted bilayer graphene model

Imagestacking two sheets of graphene – the 2D form of graphite, or the pencil at your hand – in which the carbon atoms form a hexagonal lattice and twist the top sheet out of alignment with the sheet below, yielding a periodic arrangement of atoms named moiré pattern. Do you know that at a twisted angle of about 1o – people now call it the ‘magic’ angle – the system could exhibit very exotic behaviours such as becoming an insulator, a metal or even a superconductor? Can you imagine the same carbon atom in your pencil (graphite) becoming a superconductor when twisted to the magic angle? It indeed did as people discovered it in 2018, but why? Continue reading


白石道人姜夔,南宋词人,一生布衣游食四方,存词只有80余首,不算高产(虽然他21岁写下的《扬州慢·淮左名都》入选中学语文课本,诸君可以想想自己21岁时在做什么)。但在他43岁那年的正月里,情感不知为何受到了大的扰动,爆发似的一口气写下一组五首《鹧鸪天》(准确地说是从正月初一到正月十六,从第一首《鹧鸪天 • 丁巳元日》到第五首 《鹧鸪天 • 十六夜出》),曲折地追怀自己生命中一段年轻的爱情,五首皆为精品。 Continue reading

Higgs mode via dimensional crossover in quantum magnets

The Higgs mode or the Anderson-Higgs mechanism (named after another Nobel Laureate Philip W ANDERSON), has widespread influence in our current understanding of the physical law for mass ranging from particle physics - the elusive “God particle” Higgs boson discovered in 2012 to the more familiar and important phenomena of superconductors and magnets in condensed matter physics and quantum material research. Continue reading


发明量子多体问题算法的人,多与普通人不同。他们身上有一种得道高僧、终南隐士的先知之气,往往想要扬弃和重新评价流俗所看重的种种价值观念,率性而为以至于不被社会所理解,甚至被视为狂士和疯子。这其中的原因,恐怕还是来自于在量子多体问题中发明算法本身的难度。Continue reading

Correlation-Induced Insulating Topological Phases at Charge Neutrality in Twisted Bilayer Graphene

Twisted bilayer graphene (TBG) consists of two stacked layers of graphene rotated relative to one another. With a twist angle of about 1.10° the so-called “magic” angle, many unconventional electronic behaviors emerge, including superconductivity and correlated insulators, a type of insulating phase that arises from interactions between electrons. Elucidating the mechanism responsible for these electronic states in magic-angle TBG is a problem at the frontier of quantum materials research. To help solve this problem, we employ an unbiased quantum many-body numerical method (quantum Monte Carlo simulations) to investigate the possible insulating phases of TBG. Continue reading "Correlation-Induced Insulating Topological Phases at Charge Neutrality in Twisted Bilayer Graphene"

Evidence of the topological KT phase of TMGO

Quantum materials are becoming the cornerstone for the continuous prosperity of human society, including the next-generation AI computing chips that go beyond Moore’s law, the high-speed Maglev train, and the topological unit for quantum computers, etc. However, these complicated systems require modern computational techniques and advanced analysis to reveal their microscopic mechanism. Continue reading

The search of non-Fermi liquid

Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search of knowledge, and unbearable pity for the suffering of mankind.

—Bertrand Russell

As Russell nicely put it, scientists are often driven by strong passions for the search of knowledge, such search not only benefits the human society, but often times brings the ecstasy to themselves -- the ecstasy for instance of understanding the hearts of men, knowing why the stars shine, and apprehending the Pythagorean power by which number holds sway above the flux -- that is so great that scientists would often have endured the long hours of working and sleepless nights for the pursuit of such joy. Continue reading "The search of non-Fermi liquid"




人的一辈子,乱乱哄哄、热热闹闹,其实很快就过去了。浮名与虚誉、诱惑与利益,很多时候更是在加速这个过程。时间积分之后,烦恼总是大于欢欣的。这样一个悖论,古今中外多少人都看得明白,比如大书法家王羲之,其所言如上所抄录很是通透。Continue reading

Quantum Material research connecting physicists in Hong Kong, Beijing and Shanghai

A joint research team from The University of Hong Kong (HKU), Institute of Physics at Chinese Academy of Science, Songshan Lake Materials Laboratory, Beihang University in Beijing and Fudan University in Shanghai, provide a successful example of modern era quantum material research.  Continue reading

Breakthrough in Understanding Quantum Metals

Metals, especially interacting metallic states, never stop surprising people. Among the interesting phenomena that have emerged is the “high-temperature” superconductivity. This holds great promise for enabling highly-efficient energy transportation, but it can be achieved only at extremely cold temperatures (about -100 degrees Celsius or below) that are currently too costly and energy-intensive to replicate. Continue reading