Adiabatic quantum computing (AQC) started as an approach to solving optimization
problems and has evolved into an important universal alternative to the standard circuit …

Current technology is beginning to allow us to manipulate rather than just observe individual
quantum phenomena. This opens up the possibility of exploiting quantum effects to perform …

A digital computer is generally believed to be an efficient universal computing device; that is,
it is believed to be able to simulate any physical computing device with an increase in …

We show that a set of gates that consists of all one-bit quantum gates [U (2)] and the two-bit
exclusive-O R gate [that maps Boolean values (x, y) to (x, x⊕ y)] is universal in the sense …

If the bits of computers are someday scaled down to the size of individual atoms, quantum
mechanical effects may profoundly change the nature of computation itself. The wave …

Computers are physical systems: the laws of physics dictate what they can and cannot do. In
particular, the speed with which a physical device can process information is limited by its …

In some of the earliest work on quantum computing, Feynman showed how to implement
universal quantum computation with a time-independent Hamiltonian. I show that this …

We discuss the problem of counting the maximum number of distinct states that an isolated
physical system can pass through in a given period of time—its maximum speed of …

It is shown that if one can apply some Hamiltonian repeatedly to a few variables at a time
one can in general effect any desired unitary time evolution on an arbitrarily large number of …

A natural architecture for nanoscale quantum computation is that of a quantum cellular
automaton. Motivated by this observation, we begin an investigation of exactly unitary …