Condensed Matter/Materials & Biological Physics Seminar with Shubhayu Chatterjee on Quantum Noise Spectroscopy

Continuous phase transitions exhibit remarkable universality across disparate physical systems. Such transitions are characterized by the nature of fluctuations near the critical point. We will discuss a route towards quantum sensing of critical points via noise spectroscopy. We will 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 applies to both 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. If time permits, we will illustrate our proposal by using it to uncover surface critical phenomena in metallic Gadolinium.