Abstract
Higgs oscillations in nonequilibrium superconductors provide an unique tool to obtain information about the underlying order parameter. Several properties like the absolute value, existence of multiple gaps and the symmetry of the order parameter can be encoded in the Higgs oscillation spectrum. Studying Higgs oscillations with time-resolved angle-resolved photoemission spectroscopy (ARPES) has the advantage over optical measurements that a momentum-resolved analysis of the condensate dynamic is possible. In this paper, we investigate the time-resolved spectral function measured in ARPES for different quench protocols. We find that analyzing amplitude oscillations of the ARPES intensity in the whole Brillouin zone allows to understand how the condensate dynamic contributes to the emerging of collective Higgs oscillations. Furthermore, by evaluating the phase of these oscillations the symmetry deformation dynamic of the condensate can be revealed, which gives insight about the ground state symmetry of the system. With such an analysis, time-resolved ARPES experiments might be used in future as a powerful tool in the field of Higgs spectroscopy.
Highlights
Angle-resolved photoemission spectroscopy (ARPES) is a powerful method as it allows to measure the electronic structure of materials directly [1]
We demonstrate how the collective Higgs oscillations of the superconducting order parameter can be traced back and be observed as oscillations of the ARPES intensity measured in THz tr-ARPES experiments
There are two kinds of dynamics, namely momentum-independent oscillations of the energy distribution curve (EDC) maximum E (t ), which directly correspond to oscillations of the energy gap (t ), and momentumdependent oscillations of the amplitude of the ARPES intensity A(t, k, φ)
Summary
Angle-resolved photoemission spectroscopy (ARPES) is a powerful method as it allows to measure the electronic structure of materials directly [1]. We allow arbitrary gap symmetry and study the effect of quenches in symmetry channels different from the ground state The idea behind such quenches is to model the net effect of pump pulses in a controlled way, which act on the condensate momentum-dependently. These might be realized experimentally by tuning polarization and pulse direction [28] or could be implemented in more complex approaches like transient grating [39,40] or four-wave mixing [41] setups Quenching superconductors with such an approach, where the symmetry of the condensate is altered with respect to the ground state, can result in dynamically created additional Higgs modes [28]. A calculation of the oscillation phase in different lobes shows opposite phase oscillations, reflecting the differently induced symmetry deformations of the condensate in momentum space
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
