Quantum phase transition induced by real-space topology

TL;DR

This paper demonstrates a second-order quantum phase transition triggered by changing the real-space topology of a honeycomb lattice system, linking topology with quantum criticality.

Contribution

It reveals a novel type of quantum phase transition induced solely by topological changes in the system's real-space geometry.

Findings

Ground state undergoes a second-order QPT when topology changes from torus to tube.

The transition exhibits characteristic scaling behavior.

The work establishes a connection between real-space topology and quantum phase transitions.

Abstract

A quantum phase transition (QPT), including both topological and symmetry breaking types, is usually induced by the change of global parameters, such as external fields or global coupling constants. In this work, we demonstrate the existence of QPT induced by the real-space topology of the system. We investigate the groundstate properties of the tight-binding model on a honeycomb lattice with the torus geometry based on exact results. It is shown that the ground state experiences a second- order QPT, exhibiting the scaling behavior, when the torus switches to a tube, which reveals the connection between quantum phase and the real-space topology of the system.