Superconductors with spin–orbit interactions

2016 ◽  
Vol 30 (25) ◽  
pp. 1650183 ◽  
Author(s):  
Yu. N. Ovchinnikov

The effect of spin-orbit (SO) interaction on the formation of the critical states in thin superconducting films in magnetic field oriented along the film is investigated. Hereby, the case of interband pairing is considered. It was found that eight branches exist in the plane of two parameters [Formula: see text] determined by the value of magnetic field and SO interaction. Six modes leads to inhomogeneous states with different values of the impulse [Formula: see text]. Each state is doubly degenerate over direction of impulse [Formula: see text]. The parameter values at critical point are found for all eight branches in explicit form for zero temperature. The optimal two branches are estimated, corresponding to largest critical magnetic field value for given SO interaction.

1999 ◽  
Vol 13 (17) ◽  
pp. 2229-2256 ◽  
Author(s):  
FEI ZHOU

A theory of mesoscopic fluctuations in disordered thin superconducting films in a parallel magnetic field is developed. At zero temperature and at a sufficiently strong magnetic field, the superconducting state undergoes a phase transition into a state characterized by superfluid densities of random signs, instead of a spin polarized disordered Fermi liquid phase. Consequently, in this regime, random supercurrents are spontaneously created in the ground state of the system, which belongs to the same universality class as the two dimensional XY spin glass. As the magnetic field increases further, mesoscopic pairing states are nucleated in an otherwise homogeneous spin polarized disordered Fermi liquid. The statistics of these pairing states is universal depending on the sheet conductance of the two-dimensional film.


Author(s):  
J. Nitta

This chapter focuses on the electron spin degree of freedom in semiconductor spintronics. In particular, the electrostatic control of the spin degree of freedom is an advantageous technology over metal-based spintronics. Spin–orbit interaction (SOI), which gives rise to an effective magnetic field. The essence of SOI is that the moving electrons in an electric field feel an effective magnetic field even without any external magnetic field. Rashba spin–orbit interaction is important since the strength is controlled by the gate voltage on top of the semiconductor’s two-dimensional electron gas. By utilizing the effective magnetic field induced by the SOI, spin generation and manipulation are possible by electrostatic ways. The origin of spin-orbit interactions in semiconductors and the electrical generation and manipulation of spins by electrical means are discussed. Long spin coherence is achieved by special spin helix state where both strengths of Rashba and Dresselhaus SOI are equal.


1992 ◽  
Vol 06 (16n17) ◽  
pp. 1037-1042 ◽  
Author(s):  
V. BUNTAR ◽  
U. ECKERN ◽  
C. POLITIS

The lower critical magnetic field Hc1 of superconducting Rb 3 C 60 (Tc=28.5 K ) is estimated by different methods. The zero temperature value is found to be given by Hc1=16.2±1.0 mT, and the penetration depth is λL=215±10 nm . The Bean model analysis leads to threshold fields of 5.3 mT for T=5 K , and 4.0 mT for T=17 K . The big influence of intergranular connections on Hc1 is demonstrated. Good agreement between the low- and the high-field analysis is found.


2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940016
Author(s):  
A. V. Baran ◽  
V. V. Kudryashov

Energy levels of electrons in the semiconductor circular quantum ring are obtained within the framework of perturbation theory in the presence of the Rashba and Dresselhaus spin-orbit interactions and external uniform constant magnetic field. The confinement effect is simulated by the realistic potential well of a finite depth.


1997 ◽  
Vol 8 (2) ◽  
pp. 125-148 ◽  
Author(s):  
T. BOECK ◽  
S. J. CHAPMAN

The bifurcation from a normally conducting state to a superconducting state in a decreasing magnetic field is studied for a slab geometry. The leading eigenvalue is a double eigenvalue, leading to a rich structure of possible behaviours. A weakly-nonlinear stability analysis is performed, and the possible responses of the material are classified. Finally, the leading-order equations are solved numerically for a wide range of parameter values to determine which of these behaviours will occur in practice.


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