Francisco Machado

ITAMP Fellow | Harvard University



Quantum noise spectroscopy of dynamical critical phenomena | Francisco Machado

Quantum noise spectroscopy of dynamical critical phenomena

Francisco Machado, Eugene A. Demler, Norman Y. Yao, Shubhayu Chatterjee
PRL (2023)
arXiv:2211.02663

Abstract

The transition between distinct phases of matter is characterized by the nature of fluctuations near the critical point. We demonstrate that noise spectroscopy can not only diagnose the presence of a phase transition, but can also determine fundamental properties of its criticality. In particular, by analyzing a scaling collapse of the decoherence profile, one can directly extract the critical exponents of the transition and identify its universality class. Our approach naturally captures the presence of conservation laws and distinguishes between classical and quantum phase transitions. In the context of quantum magnetism, our proposal complements existing techniques and provides a novel toolset optimized for interrogating two-dimensional magnetic materials.