Spectral evidence for Dirac spinons in a kagome lattice antiferromagnet

A collaboration between theoretical physicists Dr. Chengkang ZHOU and Professor Zi Yang MENG from the Department of Physics at The University of Hong Kong (HKU), along with experimentalists Mr. Zhenyuan ZENG and Professor Shiliang LI at the Institute of Physics (IOP), Chinese Academy of Sciences (CAS), and Professor Kenji NAKAJIMA from J-PARC Center, Japan, has led to a discovery in the realm of quantum physics. Their study, published in a recent issue of Nature Physics (Nat. Phys. (2024)), sheds light on the long-anticipated emergence of quasiparticles, akin to the famous Dirac particles obeying the relativistic Dirac equation. These quasiparticles, known as Dirac spinons, were theorised to exist within a novel quantum state called a quantum spin liquid state. This work captures the conic spin excitations arising from Dirac spinons, resulting in low-energy spin excitations with sharp energy-momentum characteristics. Their results provide strong evidence for the emergence of a Dirac quantum spin liquid state in YCu3-Br. Continue reading

亚得里亚海边的回忆

科学事业的传承,创造性精神的传承,在我们的文化基因中是如此地难能可贵,过去的十年,二十年,三十年,似乎在我们的历史上成为了偶然,而如今的我们却必然地向着科举之下的干谒、八股和满街的勋宗们靠近,离玻尔兹曼、乔伊斯、茨维格和人类群星闪耀着的的里雅斯特的美好年代,离亚得里亚海边柔和的晚风和灯光越来越远。Continue reading