Deconfined Quantum Critical Point with Non-locality

TL;DR

This paper explores a novel mechanism for nonlocal interactions at the deconfined quantum critical point (DQCP), specifically through coupling to Fermi surface hot spots, revealing a new fixed point with altered dynamical properties.

Contribution

It introduces a new way to generate nonlocal interactions at the DQCP via coupling to Fermi surface hot spots, expanding the understanding of quantum criticality.

Findings

Identification of a new fixed point with dynamical exponent z > 1

Demonstration of nonlocal interactions influencing DQCP physics

Control of DQCP behavior within a specific energy window

Abstract

The deconfined quantum critical point (DQCP) between the N\'{e}el and valence bond solid (VBS) order was originally proposed in quantum spin systems with a local Hamiltonian. In the last few years analogues of DQCPs with nonlocal interactions have been explored, which can lead to rich possibilities. The nonlocal interactions can either arise from an instantaneous long range interaction in the Hamiltonian, or from gapless modes that reside in one higher spatial dimension. Here we consider another mechanism of generating nonlocal interactions by coupling the DQCP to the "hot spots" of a Fermi surface. We demonstrate that at least within a substantial energy window, the physics of the DQCP is controlled by a new fixed point with dynamical exponent $z > 1$