Bosonic Anomalies in Boron-Doped Polycrystalline Diamond

作者:Zhang, Gufei*; Samuely, Tomas; Kacmarcik, Jozef; Ekimov, Evgeny A.; Li, Jun; Vanacken, Johan; Szabo, Pavol; Huang, Junwei; Pereira, Paulo J.; Cerbu, Dorin; Moshchalkov, Victor V.
来源:Physical Review Applied, 2016, 6(6): 064011.
DOI:10.1103/PhysRevApplied.6.064011

摘要

Quantum confinement and coherence effects are considered the cause of many specific features for systems which are generally low dimensional, strongly disordered, and/or situated in the vicinity of the metal-insulator transition. Here, we report on the observation of anomalous resistance peak and specific heat peaks superimposed at the superconducting transition of heavily boron-doped polycrystalline bulk diamond, which is a three-dimensional system situated deep on the metallic side of the boron-doping-driven metal-insulator transition in diamond. The anomalous resistance peak and specific heat peaks are interpreted as a result of confinement and coherence effects in the presence of intrinsic and extrinsic granularity. Our data, obtained for superconducting diamond, provide a reference for understanding the superconductivity in other granular disordered systems. Furthermore, our study brings attention to the significant influence of granular disorder on the physical properties of boron-doped diamond, which is considered a promising candidate for electronics applications.