Japanese | |

## Tsuneyuki Research Group |

Precise prediction of superconducting transition temperature (*T _{C}*) is one of the grand challenges in first principle calculations. We are developing a numerical code based on density functional theory for superconductors (SCDFT), and applying to a few superconducting materials.

SCDFT is one of extensions of density functional theory (DFT). In the framework of SCDFT, we minimize the free energy as a functional of electron density and a superconducting order parameter. The order parameter obtained by this minimization becomes globally 0 above *T _{C}*. Moreover, in SCDFT, we can obtain quasi-particle excitation spectra and superconducting gap functions from the non-interacting Kohn-Sham reference system in the self-consistent field.

We show results of an application of our program to magnesium diboride (MgB_{2}), which has the highest *T _{C}* in phonon-induced type superconductors. Figure 1 shows the magnitude of gap functions on the Fermi surface of MgB

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