Josephson detection of time-reversal symmetry broken superconductivity in SnTe nanowires

A Josephson junction (JJ) couples the supercurrent flowing between two weakly linked superconductors to the phase difference between them via a current-phase relation (CPR). While a sinusoidal CPR is expected for conventional junctions with insulating weak links, devices made from some exotic materials may give rise to unconventional CPRs and unusual Josephson effects. In this work, we present such a case: we investigate the proximity-induced superconductivity in SnTe nanowires by incorporating them as weak links in JJs and observe a deviation from the standard CPR. We report on indications of an unexpected breaking of time-reversal symmetry in these devices, detailing the unconventional characteristics that reveal this behavior. These include an asymmetric critical current in the DC Josephson effect, a prominent second harmonic in the AC Josephson effect, and a magnetic diffraction pattern with a minimum in critical current at zero magnetic field. The analysis examines how multiband effects and the experimentally visualized ferroelectric domain walls give rise to this behavior, giving insight into the Josephson effect in materials that possess ferroelectricity and/or multiband superconductivity.

Leading role of the principles of interaction between the natural physical factors and integral organism in medicine of the future

The paper discusses the search of evidences of advantage of the physiotherapy over the drug therapy by the parameters and treatment methods according to clinical stage of a disease development, based on the results of labor medical examination and improvement of the quality of life. The above indicators were confirmed with a high statistical accuracy by example of a new rehabilitation technology: "Underwater horizontal spine traction with underwater phototherapy to solve an essential medical and social problem: treatment of patients with degenerative and dystrophic lesions of the lumbosacral spine with herniated protrusions of intervertebral discs, being one of the most common neurological pathologies worldwide. Based on the achievements in physics, i.e. discovery of "evanescent waves", "scanning tunneling microscope"; "AC and DC Josephson effects", development of highly sensitive equipment and discovery by the author of the present article of a highly informative, non-invasive, simple, harmless method of studying the mechanism of action of physical factors on the integral organism from any part of the skin surface, i.e. "blood spectrum biopsy" displaying the complete information picture of an organism, it became possible to create a new theory of a mechanism of action of physical factors on the supramolecular level of the integral organism on the principle of "tunnel effect".

Consequences of Brian Josephson’s Theoretical Discovery

Theoretical discovery of Josephson effects has beneficial consequences for science and economy, and in the future promises more benefits for public health. The strongest impact thus far has the use of Josephson devices and circuits in many areas of science and in geophysical prospecting for minerals. I highlight a few examples of present and future benefits.

Theory of generalized Josephson effects

The DC Josephson effect is the flow of supercurrent across a weak link between two superconductors with different values of their order parameters, the phase. We formulate this notion for any kind of spontaneous continuous symmetry breaking. The quantity that flows between the two systems is the zero-wavenumber Noether current associated with the broken symmetry. The AC Josephson effect is the oscillation of current due to the energy difference between the two systems caused by an imposed asymmetric chemical potential of Noether charge. As an example of novel physics, a Josephson effect is predicted between two crystalline solids, potentially measurable as a force periodic in the separation distance.

Superconductivity

Superconductivity and the associated Meissner effect are introduced, indicating that superconductors are perfect diamagnetics. Condensation energy is deduced. The London analysis showing how superconductors exclude flux is presented. The BCS microscopic theory is recapitulated: Cooper pairs of electrons are the constituents of the Bose condensate that carries the non-dissipative current. The binding energy of pairs (energy gap below the Fermi sea) is deduced and related to their size and the critical temperature. Dependence of the energy gap on temperature is shown consistent with BCS theory. The Ginzberg–Landau analysis and the spontaneous symmetry breaking in the condensate phase are recounted. Quantization of trapped magnetic flux is shown to be related to superconductor topology. Type-II superconductors are treated. Finally Josephson effects show unambiguously that the condensate is a macroscopic quantum state. Josephson applications are enumerated, including a new voltage standard, SQUIDs and preliminary versions of qubits (transmons) for quantum computing.