Quasiparticle density of states of 2H-NbSe{sub 2} single crystals revealed by low-temperature specific heat measurements according to a two-component model.
- Materials Science Division
Low-temperature specific heat in a dichalcogenide superconductor 2H-NbSe{sub 2} is measured in various magnetic fields. It is found that the specific heat can be described very well by a simple model concerning two components corresponding to vortex normal core and ambient superconducting region, separately. For calculating the specific heat outside the vortex core region, we use the Bardeen-Cooper-Schrieffer (BCS) formalism under the assumption of a narrow distribution of the superconducting gaps. The field-dependent vortex core size in the mixed state of 2H-NbSe{sub 2}, determined by using this model, can explain the nonlinear field dependence of specific heat coefficient {gamma}(H), which is in good agreement with the previous experimental results and more formal calculations. With the high-temperature specific heat data, we can find that, in the multi-band superconductor 2H-NbSe{sub 2}, the recovered density of states (or Fermi surface) below T{sub c} under a magnetic field seems not to be gapped again by the charge density wave (CDW) gap, which suggests that the superconducting gap and the CDW gap may open on different Fermi surface sheets.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); National Natural Science Foundation of China (NNSFC); State Key Development for Basic China Research Grant
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 1010901
- Report Number(s):
- ANL/MSD/JA-68926; TRN: US201109%%168
- Journal Information:
- Chinese Phys. B, Vol. 17, Issue 6 ; Jun. 2008
- Country of Publication:
- United States
- Language:
- ENGLISH
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