Enhanced 2π2\pi-periodic Aharonov-Bohm Effect as a Signature of Majorana Zero Modes Probed by Nonlocal Measurements

We propose the $2\pi$-periodic Aharonov-Bohm (AB) effect as a nonlocal probe of Majorana zero modes (MZMs) without the restriction of fermion parity. We demonstrate the enhancement of the AB effect, where the topological protection of MZMs yields amplified and robust Andreev reflection mediated by MZMs at multiple superconductor-normal metal junctions. We investigate the influence of trivial bound states and show that a nonlocal index enables a more explicit distinction between the trivial and topological bound states than local probes.Comment: 9 pages, 11 figure

Possible Realization of Topological Crystalline Superconductivity with Time-Reversal Symmetry in UTe2

The recent measurement of the de Haas-van Alphen effect in the spin-triplet superconductor UTe2 [D. Aoki et al., J. Phys. Soc. Jpn. 91, 083704 (2022)] supports cylindrical electron and hole Fermi surfaces, which implies that UTe2 is trivial as a 3D time-reversal-invariant topological superconductor. Inspired by this observation, we investigate the possible realization of a topological crystalline superconductor protected by the crystalline symmetry of UTe2. We examine Majorana surface states protected by mirror and two-fold rotational symmetries for all symmetry-allowed odd-parity pairing states with time-reversal symmetry and clarify the corresponding topological invariants. It is found that topological crystalline superconductivity can be realized for all irreducible representations of odd-parity pairing states of UTe2 even for cylindrical Fermi surfaces.Comment: 12 pages, 7 figure

Engineering Yang-Lee anyons via Majorana bound states

We propose the platform of a Yang-Lee anyon system which is constructed from Majorana bound states in topological superconductors. Yang-Lee anyons, described by the non-unitary conformal field theory with the central charge $c=-22/5$, are non-unitary counterparts of Fibonacci anyons, obeying the same fusion rule, but exhibiting non-unitary non-Abelian braiding statistics. We consider a topological superconductor junction system coupled with dissipative electron baths, which realizes a non-Hermitian interacting Majorana system. Numerically estimating the central charge, we examine the condition that the non-Hermitian Majorana system can simulate the Ising spin model of the Yang-Lee edge singularity, and confirm that, by controlling model parameters in a feasible way, the Yang-Lee edge criticality is realized. On the basis of this scenario, we present the scheme for the fusion, measurement and braiding of Yang-Lee anyons in our proposed setup.Comment: 12 pages, 11 figure

Non-local spin correlation as a signature of Ising anyons trapped in vacancies of the Kitaev spin liquid

In the Kitaev chiral spin liquid, Ising anyons are realized as Majorana zero modes bound in $Z_2$ fluxes, which, however, are thermal excitations with finite decay rates. On the other hand, a lattice vacancy traps a $Z_2$ flux even in the ground state, resulting in the stable realization of a Majorana zero mode in the $Z_2$ flux. We demonstrate that spin-spin correlation functions between two vacancy sites exhibit long-range correlation arising from the fractionalized character of Majorana zero modes, in spite of the strong decay of bulk spin correlations. Remarkably, this non-local spin correlation does not decrease as the distance between two vacancy sites increases, signaling teleportation of Majorana zero modes. Furthermore, we clarify that the non-local correlation can be detected electrically via the measurement of non-local conductance between two vacancy sites, which is also utilized for the readout of Majorana qubits. These findings pave the way to the measurement-based quantum computation with Ising anyons trapped in vacancies of the Kitaev spin liquid.Comment: 6 pages + 4 figures, and a Supplemental Materia

Osteoporosis due to testicular atrophy in male leprosy patients

A study was conducted to examine the relationship of testicular atrophy to bone metabolism in male leprosy patients. The study consisted of 31 leprosy patients (mean age: 62.0 years) and 31 healthy control men (mean age: 60.0 years). Measurements were made of their serum levels of free testosterone (FT), estradiol (E2), luteinizing hormone (LH) and 25-hydroxyvitamin D (25 OHD). Bone mineral density (BMD) was measured at radial sites and the lumbar vertebral bodies (L2-L4) by dual-energy X-ray absorptiometry using a Hologic QDR-2000 densitometer. FT and E2 levels were significantly lower and LH levels higher in leprosy patients than in controls. This represents a primary hypogonadal pattern. A value of 7.20pg/ml of FT (= Mean -1 SD of control) was used as a cut off value, and the subjects were subdivided into a hypogonadal group (HG) and a non hypogonadal group (non-HG). When the subjects were compared for differences in age, age at onset of disease, duration of disease, body mass index and BMD, only the duration of disease and BMD were significantly different between the two groups. Furthermore, BMD of the forearm significantly correlated with FT levels (r = 0.689, P &#60; 0.0001). Low BMD may be due to orchitis and testicular atrophy.</p