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arXiv · 2412.06569

Observation of Local Pairs through Nonequilibrium Terahertz Spectroscopy in YBa2Cu3O7-{\delta} Below Tc

Jinzhong Zhang·Qingming Huang·Zhangqiang Yang·Zhiyuan Sun·Ye Yang
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Abstract

Pairing states are essential to understanding the underlying mechanisms of high-temperature superconductivity. Here the non-superconducting state in an optimally doped YBa_2 Cu_3 O_(7-{\delta}) film was driven out of equilibrium by an optical pump with low fluence at a temperature well below the critical temperature (T_c), and its recovery dynamics were exclusively measured using transient terahertz spectroscopy. The pump-fluence dependent experiments unveiled evidence of local pairs without superconductivity coexisting with the superconducting Cooper pairs. An energy gap opening induced by the local pairing with short-range coherence was invoked to rationalize the temperature-dependent recovery time of local pairs with a characteristic divergence at a temperature substantially below T_c. These local pairs displayed remarkable likeness to the short-range pair-density-wave state. Our finding sheds light on understanding the dynamic interplay between the coexisting superconducting and non-superconducting pairs in cuprate superconductors.

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Jinzhong Zhang, Qingming Huang, Zhangqiang Yang, Zhiyuan Sun, Ye Yang. 2024-12-09. Observation of Local Pairs through Nonequilibrium Terahertz Spectroscopy in YBa2Cu3O7-{\delta} Below Tc. https://arxiv.org/abs/2412.06569

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