Higgs spectroscopy of superconductors in nonequilibrium
Research report (imported) 2017 - Max Planck Institute for Solid State Research
In superconductors, a collective excitation of Cooper pairs exists which is known as the Higgs mode. If the system is excited out of equilibrium, Higgs oscillations can arise. From these, properties of the superconducting energy gap can be deduced. In conventional superconductors the system oscillates with a frequency corresponding to two times the energy gap. In the case of unconventional superconductors multiple Higgs modes can arise. As a consequence, Higgs oscillations can serve as a spectroscopic method to retrieve information about the symmetry of the energy gap.