Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Dr Alex Gómez-Salvador, University of Oxford
Akshat Pandey <akshat.pandey@all-souls.ox.ac.uk>
Abstract
Two-Dimensional Spectroscopy in Many-Body Physics
Two-dimensional spectroscopy is emerging as a powerful tool for investigating the dynamics of collective excitations in quantum many-body systems. By resolving correlations between excitation and detection frequencies, it provides access to dynamical information that is often hidden in conventional linear spectroscopy. In this talk, I will present an overview of recent theoretical developments illustrating the potential of this approach. I will first discuss how nonlinear spectroscopic techniques can disentangle disorder-induced broadening from intrinsic relaxation processes in bosonic collective excitations, with particular emphasis on Josephson plasma modes in high-temperature superconductors. I will then turn to more recent developments concerning rephasing echoes in continua of fractionalized excitations, highlighting how rephasing signals can reveal the underlying dynamics of particle pairs and their coupling to collective modes. Finally, I will discuss how these ideas can be extended to probe fluctuations close to criticality, opening new avenues for investigating strongly correlated quantum matter.