Experimental observation of conformal field theory spectra
Sara Murciano (LPTMS)
Conformal field theories (CFTs) feature prominently in high-energy physics, and condensed matter. For example, CFTs govern emergent universal properties of systems tuned to quantum phase transitions, including their entanglement or correlations. Much of the rich structure predicted by CFTs nevertheless remains unobserved in experiment. In this talk, I will present direct observations of the energy excitation spectra of emergent CFTs at quantum phase transitions, recovering universal energy ratios characteristic of the underlying field theories. By using a variant of the modulation technique, we furthermore study the dynamical structure factor of the critical system, which is closely related to the correlation of an underlying Ising conformal field.