Learn More
There are hamiltonians that solve a search problem of finding one of N items in O(√ N) steps. They are hamiltonians to describe an oscillation between two states. In this paper we propose a generalized search hamil-tonian, Hg. Then the known search hamiltonians become special cases of Hg. From the generalized search hamiltonian, we present remarkable(More)
We consider optimal state discrimination in a general convex operational framework, so-called generalized probabilistic theories (GPTs), and present a general method of optimal discrimination by applying the complementarity problem from convex optimization. The method exploits the convex geometry of states but not other detailed conditions or relations of(More)
We study N-dimensional measurement-device-independent quantum-key-distribution protocol where one checking state is used. Only assuming that the checking state is a superposition of other N sources, we show that the protocol is secure in zero quantum-bit-error-rate case, suggesting possibility of the protocol. The method may be applied in other quantum(More)
Farhi et al. suggested the analogue quantum search Hamiltonian and Fenner also proposed the intuitive quantum search Hamiltonian. Recently the generalized quantum search Hamiltonian containning hamiltonians of Farhi et al. and Fenner was presented in quant-ph/0110020. In this letter, we analyze the running time of the generalized quantum search Hamiltonian.(More)
In this letter, we show that the laser Hamiltonian can perform the quantum search. We also show that the process of quantum search is a resonance between the initial state and the target state, which implies that Nature already has a quantum search system to use a transition of energy. In addition, we provide the particular scheme to implement the quantum(More)
  • 1