在纠缠中窥见自然的奥秘

身无彩凤双飞翼,心有灵犀一点通

——李商隐《无题》

唐代诗人李商隐的这首诗,道尽了人世间痴情男女虽天各一方、但彼此心意相通、似有一条丝线相连的缠绵。

其实,电子的世界亦如此。配对的电子,一旦形成一个纠缠态,无论相距多远,它们都能感受到彼此的心意” (自旋)。它们一个向上,一个向下,仿佛约好了似的。只要有一方改变状态,那么另一方就会立刻感受到,并且调整成与对方相反的状态。Continue reading

情愿不自由,便是自由了

时令不停流转,经过残酷阴沉荒原般的四月,到了五月,人们总会回过神来想起青年。想起身处初夏阳光中的感觉,看着满山茂盛的树木在微风中摇曳,看着蔚蓝的大海和视线尽头那一片氤氲中满是希望和新鲜的世界,多好,一切都是绿的、蓝的、清澈的、新鲜的、天真的、诚实的和健康的。Continue reading

Unitary CFT description of DQCP is denied from quantum entanglememt entropy

The research team developed a new and more efficient quantum algorithm of the Monte Carlo techniques adopted by scientists to measure the Renyi entanglement entropy of objects. With this new tool, they measured the Rényi entanglement entropy at the DQCP and found the scaling behaviour of the entropy, i.e. how the entropy changes with the system sizes, is in sharp contrast with the description of conventional LGW types of phase transitions. Continue reading

from Quantum Materials to the Origin of Black Holes

In the time of quantum technology and big data, scientists start to integrate Artificial Intelligence (AI) and computational approaches into the fundament research about our mother Nature and Universe. This series of two lectures will help us to unfold such interesting discovery processes. Dr Zi Yang MENG, Associate Professor at HKU Department of Physics, will explain the important role played by AI and computation in the modern quantum material research in the first lecture. Find more

无愁河上的浪荡汉子们

这个题目乍一看有点儿戏谑,甚至有些许少儿不宜的味道,其实《无愁河的浪荡汉子》是木刻家、画家、作家黄永玉在80多岁时开始写作的以自己为原型的人生自传,目前已经出到第三部。第一部《朱雀城》从传主张序子两岁开始,写他的太婆、爷爷、父亲母亲、姑姑和表叔们——其中一位表叔就是写出《边城》、《长河》和《中国古代服饰研究》的沈从文——一个大家族,和他们生活的朱雀古城(以湘西凤凰为原型),古城的四季时光、风俗民情与繁华时的荣耀。 Continue reading "无愁河上的浪荡汉子们"

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

关于纠缠的十四行诗

十四行诗,英文叫Sonnet,老一辈翻译家还曾根据音译翻成商籁体,很好听。其实是欧洲的格律诗,最初是小诗、小歌谣,也不一定十四行,随着历史的演进十四行诗句的格式逐渐被定型下来,而且押韵结构也有了严格的限制。在文艺复兴时的意大利,有了彼特拉克体(Petrarchan Sonnet),音韵优美,以歌颂爱情为主。一般分为两部分,前一部分由两段四行诗组成,韵脚为a-b-b-a,a-b-b-a;后一部分由两段三行诗组成,韵脚为c-d-e,c-d-e。 Continue reading "关于纠缠的十四行诗"

库伦作用无尽期,动量蒙卡寄相思

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 "库伦作用无尽期,动量蒙卡寄相思"

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

转角石墨烯的三昧

三昧是佛教里的话,是说修行的人能够止息杂念,心神平静,进入禅定,一窥事物的真谛。我们这些俗人,又生活在俗世,每天都在吃喝拉撒中辗转,应付尚且不足,禅定更不可及,离三昧境盖益远矣。大先生有篇著名的文章,叫《世故三昧》,很短,很有趣,把在人世间难得三昧的窘境和苦境写得通透,感兴趣的读者可以找来看看,一定强过阅读下面带着公式和图表的物理八股。 Continue reading "转角石墨烯的三昧"