Spin-nematic order in the frustrated pyrochlore-lattice quantum rotor model

TL;DR

This paper demonstrates that quantum fluctuations induce a long-range spin-nematic ordered phase in a frustrated pyrochlore-lattice quantum rotor model, with a first-order phase transition, as shown by quantum Monte Carlo simulations.

Contribution

It reveals the emergence of spin-nematic order due to quantum fluctuations in a frustrated lattice, extending understanding of quantum phase transitions in such systems.

Findings

Quantum fluctuations induce long-range spin-nematic order.

The ordered phase persists at finite temperatures.

The phase transition appears to be first order.

Abstract

As an example of ordering due to quantum fluctuations, we examine the nearest-neighbor antiferromagnetic quantum O(n) rotor model on the pyrochlore lattice. Classically, this system remains disordered even at zero temperature; we find that adding quantum fluctuations induces an ordered phase that survives to positive temperature, and we determine how its phase diagram scales with the coupling constant and the number of spin components. We demonstrate, using quantum Monte Carlo simulations, that this phase has long-range spin-nematic order, and that the phase transition into it appears to be first order.