Phys.org May 5, 2023
A team of researchers in the USA (Rutgers University, Harvard University, University of Connecticut, Louisiana State University, Flatiron Institute, Princeton University) proposed how to experimentally manipulate the quasiparticles, in very thin layers of ordinary superconductors to create topological superconductors by slightly twisting the stacked layers. They theorized that the application of a current makes the quasiparticles in the superconductor behave as if they were in a topological superconductor. They theorized that the twist at any angle essentially determines the properties. Even deviations by .1 degree in twist is strongly detrimental. The interactions between quasiparticles are shown to lead to the emergence of a correlated superconducting state breaking time-reversal symmetry in the vicinity of the magic angle. Estimates of the magic angle in a variety of nodal superconductors are presented, ranging from the cuprates to the organic and heavy-fermion superconductors, all of which are shown to be promising for the experimental realization of their proposal… read more. TECHNICAL ARTICLE  1 ,  2Â
Momentum-space schematic of a twisted nodal superconductor exemplified by a d-wave superconductor with a sign-changing gap… Credit: Phys. Rev. Lett. 130, 186001,4 May 2023Â