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Physics Department Presents A Condensed Matter Theory Seminar

Condensed Matter Theory:

Emergence of a Field-Drive U(1) Spin Liquid in the Kitaev Honeycomb Model 


Ciaran Hickey 

University of Cologne, Germany 


In the field of quantum magnetism, the exactly solvable Kitaev honeycomb model serves as a paradigm for the fractionalization of spin degrees of freedom and the formation of Z_2 quantum spin liquids. In this talk, I will discuss the complete phase diagram of the model in an external magnetic field and focus on the emergence of a distinct gapless quantum spin liquid at intermediate field strengths. Analyzing a number of static, dynamical, and finite temperature quantities using numerical exact diagonalization techniques, I will present strong evidence that this phase exhibits gapless fermions coupled to a massless U(1) gauge field. The emergence of such a phase, via an Anderson-Higgs transition, can be naturally understood within the framework of fermionic partons.

Lastly, I will briefly discuss its stability in the presence of perturbations that naturally arise in spin-orbit entangled candidate materials.

Wednesday, March 20, 2019 at 4:00pm to 5:00pm

Dana Research Center, 114 Dana Research Center

Event Type



COS, Physics

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