Precursor effects of the superconducting state caused by d-wave phase fluctuations above T-c

Article

关键词: UNDERDOPED BI2SR2CACU2O8+DELTA;    TUNNELING SPECTROSCOPY;    FERMI-LIQUID;    PSEUDOGAP;    NMR;    YBA2CU3O6+X;    SUSCEPTIBILITIES;    BEHAVIOR;    ORIGIN;    GAP;   

DOI  :  10.1103/PhysRevB.74.134510

来源: SCIE

【 摘 要 】

One of the hallmarks of high-temperature superconductors is a pseudogap regime appearing in the underdoped cuprates above the superconducting transition temperature T-c. The pseudogap continously develops out of the superconducting gap. In addition, high-frequency conductivity experiments show a superconducting scaling of the optical response in the pseudogap regime, pointing toward a superconducting origin of the pseudogap. The phase-fluctuation vortex scenario is further supported by the measurement of an unusually large Nernst signal above T-c and the recently observed field-enhanced diamagnetism that scales with the Nernst signal. In this paper, we use a simple phenomenological model to calculate the paraconductivity and magnetic response caused by phase fluctuations of the superconducting order parameter above T-c. Our results are in agreement with experiments such as the superconducting scaling of the optical response and the spin (or Pauli) susceptibility, and further strengthen the idea of a phase-fluctuation origin of the pseudogap.

【 授权许可】

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