Unconventional spectral signature of Tc in a pure d-wave superconductor

Dec. 1 11:40-12:05

*Makoto Hashimoto1
SLAC National Accelerator Laboratory1

Angle-resolved photoemission spectroscopy (ARPES) has been an important tool to study the electronic phase diagram of high-Tc cuprate superconductors [1]. With the recent instrumentation improvements, ARPES measurements in the normal state with unprecedented precision became possible, revealing that the incoherent strange metal abruptly reconstructs into a more conventional metal with quasiparticles across the putative critical doping around 19%, concomitant with the collapse of the pseudogap, defining a temperature-independent vertical phase boundary [2]. In this talk, we focus on the overdoped regime above such critical doping to study the spectroscopic signature of superconducting fluctuations above Tc. Combined with theoretical calculations, the result suggests that the antinodal shallow band bottom is playing an important role for the fluctuating superconductivity [3]. Furthermore, we demonstrate that ARPES-derived electronic specific heat reproduces the specific heat peak at Tc, making direct connection between ARPES spectra and thermodynamic property [4]. We show that this thermodynamic anomaly arises from the singular growth of in-gap spectral intensity across Tc with strong superconducting phase fluctuation.

[1] M. Hashimoto, I. M. Vishik, R.-H. He, T. P. Devereaux, Z.-X. Shen, Nat Phys 10, 483 (2014)
[2] S.-D. Chen*, M. Hashimoto* et al., Science 366, 1099 (2019)
[3] Y. He et al., Phys Rev X 11, 031068 (2021)
[4] S.-D. Chen*, M. Hashimoto* et al., Nature 601, 562 (2022)

Keywords: High-Tc cuprates, ARPES