Eigenpath traversal by phase randomization (2009)
Boixo, Sergio, Knill, Emanuel, Somma, Rolando
A computation in adiabatic quantum computing is implemented by traversing a path of nondegenerate eigenstates of a continuous family of Hamiltonians. We introduce a method that traverses a...
Somma, Rolando, Barnum, Howard, Ortiz, Gerardo, Knill, Emanuel
We consider quantum computational models defined via a Lie-algebraic theory. In these models, specified initial states are acted on by Lie-algebraic quantum gates and the expectation values of Lie...
Barnum, Howard, Ortiz, Gerardo, Somma, Rolando, Viola, Lorenza
We define what it means for a state in a convex cone of states on a space of observables to be generalized-entangled relative to a subspace of the observables, in a general ordered linear spaces...
Entanglement as an Observer-Dependent Concept: An Application to Quantum Phase Transitions (2004)
Ortiz, Gerardo, Somma, Rolando, Barnum, Howard, Knill, Emanuel, Viola, Lorenza
This paper addresses the following main question: Do we have a theoretical understanding of entanglement applicable to a full variety of physical settings? It is clear that not only the assumption of...
Entanglement beyond subsystems (2004)
Viola, Lorenza, Barnum, Howard, Knill, Emanuel, Ortiz, Gerardo, Somma, Rolando
We present a notion of generalized entanglement which goes beyond the conventional definition based on quantum subsystems. This is accomplished by directly defining entanglement as a property of...
Nature and Measure of Entanglement in Quantum Phase Transitions (2004)
Somma, Rolando, Ortiz, Gerardo, Barnum, Howard, Knill, Emanuel, Viola, Lorenza
Characterizing and quantifying quantum correlations in states of many-particle systems is at the core of a full understanding of phase transitions in matter. In this work, we continue our...
A subsystem-independent generalization of entanglement (2003)
Barnum, Howard, Knill, Emanuel, Ortiz, Gerardo, Somma, Rolando, Viola, Lorenza
We introduce a generalization of entanglement based on the idea that entanglement is relative to a distinguished subspace of observables rather than a distinguished subsystem decomposition. A pure...
Quantum Simulations of Physics Problems (2003)
Somma, Rolando, Ortiz, Gerardo, Knill, Emanuel, Gubernatis, James
If a large Quantum Computer (QC) existed today, what type of physical problems could we efficiently simulate on it that we could not simulate on a classical Turing machine? In this paper we argue...