清华大学高等研究院教授。1978年考入中国科大少年班，1987年在中国科大物理系获博士学位。在休斯顿大学和德州超导中心做博士后和任研究职位多年。2001年加入清华大学高等研究院（中心），2004年任杨振宁讲席教授。目前主要研究方向与兴趣：凝聚态物理理论尤其是量子多体强关联系统的研究，包括各种emergent现象特别是非常规高温超导机理的探索。

摘要:

In a Mott insulator, strong on-site repulsion localizes electrons into neutral moments, which order antiferromagnetically (AFM) in the ground state. Mott physics concerns how doping disrupts this half-filled AFM state, producing a short-range AFM state akin to a resonating-valence-bond (RVB) condensate in which the doped charges become high-Tc superconducting. The key challenge in the doped Mott insulator is the emergence of a new sign structure that replaces conventional Fermi statistics in the Hilbert space truncated by the Mott gap — an intrinsically non-perturbative problem. Through a duality transformation, this sign structure can be precisely captured as a topological gauge structure, rendering the doped Mott insulator systematically tractable within a generalized mean-field and perturbative field-theory framework. I will discuss the single-hole and two-hole wavefunctions as the simplest examples, which reproduce all nontrivial features found in exact numerical calculations. At finite doping, this framework yields a series of consequences: hour-glass spin excitations of the RVB state, domes in Tc and superfluid density, Fermi arcs, and strange-metal behavior at higher temperatures and larger doping — all consistent with high-Tc phenomenology in the cuprates. All of these results can be traced back to the novel phase-string sign structure of the doped Mott insulator.