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Caltech
Division of Physics, Mathematics and Astronomy

Olexei I. Motrunich

Professor of Theoretical Physics
B.S., University of Missouri (Columbia), 1996; Ph.D., Princeton University, 2001. Assistant Professor, Caltech, 2006-12; Professor, 2012-.

Research Interests: Strongly correlated systems; Spin liquids and non-Fermi liquids in model and realistic systems; Topological phases; Quantum many-body dynamics and thermalization; Unusual thermalization, symmetries, and hydrodynamics; Numerical approaches.

Overview

I am a condensed matter theorist interested in topological phases and gapless fractionalized phases. I have been fascinated with dual approaches thinking in terms of topological defects such as vortices in superfluids or easy-plane magnets, hedgehogs in spin systems, domain walls in easy-axis magnets, and monopoles in quantum electrodynamics, and these ideas have been very fruitful in studies of topological phases.

I have also been interested in gapless fractionalized phases, including gapless spin liquids, Bose-metals, and non-Fermi liquid phases. For my PhD, I worked on quantum systems with strong randomness, including infinite-disorder fixed point in the quantum Ising model in two dimensions as well as free-fermion localization problems with particle-hole-like symmetries in one and two dimensions.

Selected Awards

  • A. P. Sloan Foundation Fellowship (2007-2011)
  • American Physical Society Fellow, Division of Condensed Matter Physics

Selected Publications

For a complete publications list, see feeds.library.caltech.edu

Related Courses

Ph 127 ab. Statistical Physics of Interacting Systems, Phases, and Phase Transitions. 9 units (4-0-5); first, second terms, 2025-26. Prerequisites: Ph 12 c or equivalent; quantum mechanics at the level of Ph 125 ab is required for Ph 127 b; may be taken concurrently. An advanced course in statistical physics that focuses on systems of interacting particles. Part a will cover interacting gases and spin models of magnetism, phase transitions and broken symmetries, classical field theories, and renormalization group approach to collective phenomena. Part b will introduce the path-integral based quantum to classical statistical mechanics mapping, as well as dualities and topological-defects descriptions, with applications to magnets, superfluids, and gauge field theories.
Instructor: Motrunich