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Unconventional Superconductivity in MgCNi3

Klaus Voelker·Manfred Sigrist
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Abstract

A multiband superconductor with a conventional phonon mechanism can develop an unconventional state with a nontrivial order parameter phase relation between the individual bands. We propose that such a state can explain recent experimental results on MgCNi3, which are suggestive of both s-wave pairing symmetry and of unconventional superconductivity. We show that such a state gives rise to Andreev bound states, and to spontaneous currents, at surfaces and around impurities. We also investigate possible phase transitions between states with different order parameter symmetry.

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Klaus Voelker, Manfred Sigrist. 2002-08-19. Unconventional Superconductivity in MgCNi3. https://arxiv.org/abs/cond-mat/0208367

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