Demsar J, Averitt RD, Taylor AJ, Kabanov VV, Kang WN, Kim HJ, Choi EM, Lee SI. Pair-breaking and superconducting state recovery dynamics in MgB2.
PHYSICAL REVIEW LETTERS 2003;
91:267002. [PMID:
14754080 DOI:
10.1103/physrevlett.91.267002]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2003] [Indexed: 05/24/2023]
Abstract
We present studies of the photoexcited quasiparticle dynamics in MgB2 where, using femtosecond optical techniques, Cooper pair-breaking dynamics (PBD) have been temporally resolved for the first time. The PBD are strongly temperature and photoexcitation intensity dependent. Analysis of the PBD using the Rothwarf-Taylor equations suggests that the anomalous PBD arises from the fact that in MgB2 photoexcitation is initially followed by energy relaxation to high frequency phonons instead of, as commonly assumed, e-e thermalization. Furthermore, the bare quasiparticle recombination rate and the probability for pair breaking by phonons have been determined.
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