Direct microwave measurement of Andreev-bound-state dynamics in a proximitized semiconducting nanowire

The modern understanding of the Josephson effect in mesosopic devices derives from the physics of Andreev bound states, fermionic modes that are localized in a superconducting weak link. Recently, Josephson junctions constructed using semiconducting nanowires have led to the realization of superconducting qubits with gate-tunable Josephson energies. We have used a microwave circuit QED architecture to detect Andreev bound states in such a gate-tunable junction based on an aluminum-proximitized InAs nanowire. We demonstrate coherent manipulation of these bound states, and track the bound-state fermion parity in real time. Individual parity-switching events due to non-equilibrium quasiparticles are observed with a characteristic timescale $T_\mathrm{parity} = 160\pm 10~\mathrm{\mu s}$. The $T_\mathrm{parity}$ of a topological nanowire junction sets a lower bound on the bandwidth required for control of Majorana bound states

Fast secure comparison for medium-sized integers and its application in binarized neural networks

In 1994, Feige, Kilian, and Naor proposed a simple protocol for secure 3-way comparison of integers a and b from the range [0, 2]. Their observation is that for p=7, the Legendre symbol (x∣p) coincides with the sign of x for x=a−b∈[−2,2], thus reducing secure comparison to secure evaluation of the Legendre symbol. More recently, in 2011, Yu generalized this idea to handle secure comparisons for integers from substantially larger ranges [0, d], essentially by searching for primes for which the Legendre symbol coincides with the sign function on [−d,d]. In this paper, we present new comparison protocols based on the Legendre symbol that additionally employ some form of error correction. We relax the prime search by requiring that the Legendre symbol encodes the sign function in a noisy fashion only. Practically, we use the majority vote over a window of 2k+1 adjacent Legendre symbols, for small positive integers k. Our technique significantly increases the comparison range: e.g., for a modulus of 60 bits, d increases by a factor of 2.8 (for k=1) and 3.8 (for k=2) respectively. We give a practical method to find primes with suitable noisy encodings.We demonstrate the practical relevance of our comparison protocol by applying it in a secure neural network classifier for the MNIST dataset. Concretely, we discuss a secure multiparty computation based on the binarized multi-layer perceptron of Hubara et al., using our comparison for the second and third layers.</p

The levels and predictors of physical activity engagement within the treatment seeking transgender population: a matched control study

Background: Physical activity has been found to alleviate mental health problems and could be beneficial for at-risk populations, such as transgender people. This study had three aims. First, to explore the amount of physical activity that treatment seeking transgender people engage in, and to compare this to matched cisgender people. Second, to determine whether there was a difference in physical activity depending on cross-sex hormone use. Third, to determine factors which predict physical activity among treatment seeking transgender people. Method: Transgender (n=360) and cisgender people (n=314) were recruited from the UK. Participants were asked to complete questionnaires about physical activity, symptoms of anxiety and depression, self-esteem, body satisfaction and transphobia. Results: Transgender people engaged in less physical activity than cisgender people. Transgender people who were on cross-sex hormones engaged in more physical activity than transgender people who were not. In transgender people on cross-sex hormones, high body satisfaction was the best statistical predictor of physical activity while high self-esteem was the best statistical predictor in people who were not. Conclusion: Transgender people are less active than cisgender people. Cross-sex hormone treatment appears to be able to indirectly increase physical activity within this population, which may be beneficial for mental well-being