B-doped diamond: Superconductivity without Fermi surface

Superconductivity in carrier-doped silicon carbide

“…Theoretically, the superconductivity in doped semiconductors can be interpreted in terms of degree of randomness caused by the impurity band, which is related to E A [17,18,42]. When E A is large (acceptor level is deep), the randomness caused by the impurity band is large.…”

“…Investigations continue to clarify whether it originates from the holes at the top of the diamond valence band or from the boron impurity band formed above the valence band [5][6][7][8][9][10][11][12][13][14][15]. In particular, a higher-T c superconductivity in C:B has been suggested from a theoretical model by a Japanese group [16][17][18], where bonds transform into bands by carrier doping of a semiconductor. In an extension of research on C:B and Si:B, our group focused on SiC.…”

Critical concentrations of superconductor to insulator transition in (1 1 1) and (0 0 1) CVD boron-doped diamond

“…The result of the angle resolved photoemission spectroscopy (ARPES) supports this assumption [14]. On the contrary, some theoretical works indicate that superconductivity is driven by electron correlation on the impurity band [15][16][17]. In order to provide an insight into the studies of superconductivity in doped semiconductors, the quantitative data about doping dependence of T C is investigated in the wide concentration range of 1 Â 10 20 < n B < 1 Â 10 22 cm À3 , taking account of growth orientation such as (1 1 1) and (0 0 1) for the first time.…”

Superconductivity in Carbide Compounds

“…In the case of B-doped diamond, experimental and theoretical research has sought to clarify whether its metallic nature arises from the holes at the top of the diamond valence band or from the boron impurity band formed above the valence band [36][37][38][39][40][41][42][43][44][45][46][47]. In particular, a higher-T c is suggested, where bonds transform into bands by carrier-doping to a semiconductor [48][49][50].…”