5 research outputs found
Fano interference of the Higgs mode in cuprate high-Tc superconductors
Despite decades of search for the pairing boson in cuprate high-Tc
superconductors, its identity still remains debated to date. For this reason,
spectroscopic signatures of electron-boson interactions in cuprates have always
been a center of attention. For example, the kinks in the quasiparticle
dispersion observed by angle-resolved photoemission spectroscopy (ARPES)
studies have motivated a decade-long investigation of electron-phonon as well
as electron-paramagnon interactions in cuprates. On the other hand, the overlap
between the charge-order correlations and the pseudogap in the cuprate phase
diagram has also generated discussions about the potential link between them.
In the present study, we provide a fresh perspective on these intertwined
interactions using the novel approach of Higgs spectroscopy, i.e. an
investigation of the amplitude oscillations of the superconducting order
parameter driven by a terahertz radiation. Uniquely for cuprates, we observe a
Fano interference of its dynamically driven Higgs mode with another collective
mode, which we reveal to be charge density wave fluctuations from an extensive
doping- and magnetic field-dependent study. This finding is further
corroborated by a mean field model in which we describe the microscopic
mechanism underlying the interaction between the two orders. Our work
demonstrates Higgs spectroscopy as a novel and powerful technique for
investigating intertwined orders and microscopic processes in unconventional
superconductors
Phase-resolved Higgs response in superconducting cuprates
In high energy physics, the Higgs field couples to gauge bosons and fermions and gives mass to their elementary excitations. Experimentally, such couplings can be verified from the decay product of the Higgs boson, the scalar (amplitude) excitation of the Higgs field. In superconductors, Cooper pairs bear a certain analogy to the Higgs field. Coulomb interactions between the Cooper pairs give mass to the electromagnetic field, which leads to the Meissner effect. Additional coupling with other types of interactions or collective modes is foreseeable, and even highly probable for high-Tc superconductors, where multiple degrees of freedom are intertwined. The superconducting Higgs mode may reveal such couplings spectroscopically and uncover interactions directly relevant to Cooper pairing. To this end, we investigate the Higgs mode of several cuprate thin films using phase-resolved terahertz third harmonic generation (THG) to. In addition to the heavily damped Higgs mode itself, we observe a universal jump in the phase of the driven Higgs oscillation as well as a non-vanishing THG above Tc. These findings indicate coupling of the Higgs mode to other collective modes and a nonzero pairing amplitude above Tc. Our study demonstrates a new approach for investigating unconventional superconductivity. We foresee a fruitful future for phase-resolved spectroscopy in various superconducting systems
Phase-resolved Higgs response in superconducting cuprates
In high energy physics, the Higgs field couples to gauge bosons and fermions and gives mass to their elementary excitations. Experimentally, such couplings can be verified from the decay product of the Higgs boson, the scalar (amplitude) excitation of the Higgs field. In superconductors, Cooper pairs bear a certain analogy to the Higgs field. Coulomb interactions between the Cooper pairs give mass to the electromagnetic field, which leads to the Meissner effect. Additional coupling with other types of interactions or collective modes is foreseeable, and even highly probable for high-Tc superconductors, where multiple degrees of freedom are intertwined. The superconducting Higgs mode may reveal such couplings spectroscopically and uncover interactions directly relevant to Cooper pairing. To this end, we investigate the Higgs mode of several cuprate thin films using phase-resolved terahertz third harmonic generation (THG) to. In addition to the heavily damped Higgs mode itself, we observe a universal jump in the phase of the driven Higgs oscillation as well as a non-vanishing THG above Tc. These findings indicate coupling of the Higgs mode to other collective modes and a nonzero pairing amplitude above Tc. Our study demonstrates a new approach for investigating unconventional superconductivity. We foresee a fruitful future for phase-resolved spectroscopy in various superconducting systems
Research data: Fano interference between collective modes in cuprate high-Tc superconductors
Research data and metadata that was used in the corresponding publication "Fano interference between collective modes
in cuprate high-Tc superconductors" ( https://doi.org/10.1038/s41467-023-36787-4 )
Evaluation of the Robustness of Learned MR Image Reconstruction to Systematic Deviations Between Training and Test Data for the Models from the fastMRI Challenge
The 2019 fastMRI challenge was an open challenge designed to advance research in the field of machine learning for MR image reconstruction. The goal for the participants was to reconstruct undersampled MRI k-space data. The original challenge left an open question as to how well the reconstruction methods will perform in the setting where there is a systematic difference between training and test data. In this work we tested the generalization performance of the submissions with respect to various perturbations, and despite differences in model architecture and training, all of the methods perform very similarly