computer

that the exchange coupling between the dots combined with arbitrary single-qubit operations is sufficient for universal quantum computation. The presence of the valley degeneracy in the electronic band structure alters the form of the exchange coupling and in general leads to spin-valley entanglement. Here, we show

We show that universal quantum logic can be achieved using only linear optics and a quantum shutter device. With these elements, we design a quantum memory for any number of qubits and a CNOT gate which are the basis of a universal quantum computer. An interaction-free model for a quantum shutter

In classical computation, any recursive function can be computed by a universal Turing machine, and the program is independent of the value of the variable. Generalizing this universality to quantum computation, one anticipates that there is a universal quantum Turing machine which can perform any

According to Deutsch, a universal quantum Turing machine (UQTM) is able to perform, in repeating a fixed unitary transformation on the total system, an arbitrary unitary transformation on an arbitrary data state, by including a program as another part of the input state. We note that if such a UQTM

Abstract not found

It is proved that the halt scheme for a universal quantum computer originally proposed by Deutsch works without spoiling the computation. The “conflict ” pointed out recently by Myers in the defintion of a universal quantum computer is shown to be only apparent. In the context of quantum

Experimental implementations of quantum computer architectures are now being investigated in many different physical settings. The full set of requirements that must be met to make quantum computing a reality in the laboratory [1] is daunting, involving capabilities well beyond the present state

For a universal quantum computer, different quantum paths should start and complete every stage of computation simultaneously so that the programs are effective. A special case that all quantum paths arrive in the output state simultaneously is necessary to halting problem. A scheme synchronizing

illustrating entanglement, nonlocality, and quantum control logic operations are presented and discussed. The notion of universality of quantum computation is introduced and the irreducible conditions are presented. It is demonstrated that the proposed generic scenario for realization of a quantum computer