Superconducting Ferromagnetic Nanodiamond

Abstract

Superconductivity and ferromagnetism are two mutually antagonistic states in condensed matter. Research on the interplay between these two competing orderings sheds light not only on the cause of various quantum phenomena in strongly correlated systems but also on the general mechanism of superconductivity. Here we report on the observation of the electronic entanglement between superconducting and ferromagnetic states in hydrogenated boron-doped nanodiamond films, which have a superconducting transition temperature T ∼ 3 K and a Curie temperature T > 400 K. In spite of the high T, our nanodiamond films demonstrate a decrease in the temperature dependence of magnetization below 100 K, in correspondence to an increase in the temperature dependence of resistivity. These anomalous magnetic and electrical transport properties reveal the presence of an intriguing precursor phase, in which spin fluctuations intervene as a result of the interplay between the two antagonistic states. Furthermore, the observations of high-temperature ferromagnetism, giant positive magnetoresistance, and anomalous Hall effect bring attention to the potential applications of our superconducting ferromagnetic nanodiamond films in magnetoelectronics, spintronics, and magnetic field sensing.

Flux pinning and improved critical current density in superconducting boron doped diamond films

“…The work by Willem et al [13] and Zhang et al [14], showed the microscopically inhomogeneous nature of superconductivity in BDD. Importance of spin ordering and disorder have been highlighted by Zhang et al, revealing ferromagnetism [15] and anomalous resistance peak [16,17] in superconducting diamond. Furthermore, the spectroscopic studies that showed existence of hole states near the valence band maximum (VBM) using x-ray absorption spectroscopy (XAS) [18] and the angle resolved photoelectron spectroscopy (ARPES) studies of homoepitaxial BDD films by Yokoya et al which demonstrated merging of the impurity band into valence band in the metallic side of IMT [19].…”

Superconductivity in La2O2M4S6 -Type Bi-based Compounds: A Review on Element Substitution Effects

“…The applications of these compounds are not identified yet, as we have seen for hybrid superconducting-ferromagnetic thin films [86][87][88]. The study of superconducting and ferromagnetic states is important to understand the interacting mechanism of Cooper pairs and ferromagnetism [86][87][88], also hybrid superconducting-ferromagnetic systems are useful for the applications like; split-ring resonators, superconducting-spintronic devices, topological quantum computing, and magnetic-field-sensors as discussed in the reference [88]. There are many challenges to developing devices for the application purpose from the four-layer-type compounds.…”

Multifunctional biomedical applications of magnetic nanodiamond

“…10 Such structure can be realized in ND. Ferromagnetic properties of carbon nanostructures are discussed for theoretically predicted structures and are found experimentally; the methods to obtain such properties without embedding magnetic atoms are developed using mechanical, electromagnetic treatments, 11 hydrogenation, 12,13 creation defects and doping (with nonmagnetic atoms), 13 and surface state modification. 14 Additionally, spin properties of structural defects of ND are studied 15 and the applications of ND are discussed, such as magnetic resonance imaging (MRI) agent for MRI, 16 and for quantum sensing.…”