I will discuss the history and prospects for new machines and instruments as anticipated in the newly announced EU Flagship for Quantum Technology. The program of Richard Feynman, as announced almost 60 years ago, to go to the “bottom” in the miniaturization of information-processing technology, has come to fruition, and a set of well-defined technologies, in the areas of quantum computing, quantum simulation, quantum sensing and metrology, and quantum communication, have emerged. I give a perspective on the sometimes abstruse significance (...) of these coming technologies. The scientists will continue beyond these technologies to new unfoldings of quantum knowledge, whose technological significance we can barely fathom today. (shrink)
We provide an alternative view of the efficient classical simulatibility of fermionic linear optics in terms of Slater determinants. We investigate the generic effects of two-mode measurements on the Slater number of fermionic states. We argue that most such measurements are not capable (in conjunction with fermion linear optics) of an efficient exact implementation of universal quantum computation. Our arguments do not apply to the two-mode parity measurement, for which exact quantum computation becomes possible.
Recent work has shown how to use the laws of quantum mechanics to keep classical and quantum bits secret in a number of different circumstances. Among the examples are private quantum channels, quantum secret sharing and quantum data hiding. In this paper we show that a method for keeping two classical bits hidden in any such scenario can be used to construct a method for keeping one quantum bit hidden, and vice–versa. In the realm of quantum data hiding, this allows (...) us to construct bipartite and multipartite hiding schemes for qubits from the previously known constructions for hiding bits. (shrink)