Effects of a Magnetic Field on Superconductivity and Quantum Criticality in Quasi-Two-Dimensional Systems with Dirac Electrons

E. C. Marino; Lizardo H. C. M. Nunes

doi:10.1016/j.physb.2007.10.087

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arXiv · 2010.02513

Effects of a Magnetic Field on Superconductivity and Quantum Criticality in Quasi-Two-Dimensional Systems with Dirac Electrons

E. C. Marino·Lizardo H. C. M. Nunes

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Abstract

We study the effects of an external magnetic field on thensuperconducting phase diagram of a quasi-two-dimensional system of Dirac electrons at an arbitrary temperature. At zero temperature, there is a quantum phase transition connecting a normal and a superconducting phase, occurring at a critical line that corresponds to a magnetic field dependent critical coupling parameter, which should be observed in planar materials containing Dirac electrons, such as $Cu_xTiSe_2$. Moreover, the superconducting gap is obtained as a function of temperature, magnetic field and coupling parameter ($λ_{\rm R}$). From this, we extract the critical magnetic field $ B_{ c } $ as a function of the temperature. For small values of $ B_{ c } $, we obtain a linear decay of the critical field, which is similar to the behavior observed experimentally in the copper doped dichalcogenide $Cu_xTiSe_2$ and also in intercalated graphite.

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E. C. Marino, Lizardo H. C. M. Nunes. 2020-10-04. Effects of a Magnetic Field on Superconductivity and Quantum Criticality in Quasi-Two-Dimensional Systems with Dirac Electrons. https://doi.org/10.1016/j.physb.2007.10.087

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