Finding high-quality parameters is a central obstacle to using the quantum approximate optimization algorithm (QAOA). Previous work partially addresses this issue for QAOA on unweighted MaxCut problems by leveraging similarities in objective landscape among different problem instances. However, we show that more general weighted has significantly modified landscapes, with proliferation of poor ...

We develop a reliable parameter-free analytic continuation method for quantum many-body calculations. Our is based on kernel grid, causal spline, regularization using the second-derivative roughness penalty, and L-curve criterion. also averaged deviation to estimate precision of our continuation. To deal with statistically obtained data more efficiently, we further bootstrap-averaged method. In...

Quantum key distribution (QKD) enables two remote users to share a string of bits with information-theoretical security. Parameter optimization is crucial step in achieving optimal performance practical QKD systems. In general, such implemented using local search algorithm (LSA). However, LSAs inevitably fail find out the values when searched rate function nonconvex or has discontinuity first-o...

Oblivious transfer (OT) is a cryptographic primitive of central importance, in particular in twoand multi-party computation. There exist various protocols for different variants of OT, but any such realization from scratch can be broken in principle by at least one of the two involved parties if she has sufficient computing power—and the same even holds when the parties are connected by a quant...