Europhys. Lett.
Volume 74, Number 2, April 2006
Page(s) 208 - 214
Section General
Published online 15 March 2006
Europhys. Lett., 74 (2), pp. 208-214 (2006)
DOI: 10.1209/epl/i2006-10005-1

Exact simulation of multi-qubit dynamics with only three qubits

A. Olaya-Castro, C. F. Lee and N. F. Johnson

Centre for Quantum Computation and Physics Department, Clarendon Laboratory Oxford University - Parks Road, OX1 3PU, UK

received 15 January 2006; accepted in final form 20 February 2006
published online 15 March 2006

We present equivalence relations which simplify the dynamics of an important class of interacting multi-qubit systems. We show that a wide class of M+1 qubit systems, with one or M excitations, can be reduced to an equivalent n+1 qubit system with $n\geq 2$, for any M. The equivalent system faithfully reproduces the overall dynamics of the original one including the entanglement properties. In addition to its direct application to qubit-cavity systems, the formalism offers insight into a variety of situations ranging from decoherence due to a spin-bath with its own internal entanglement, through to energy transfer processes in organic systems such as biological photosynthetic units.

03.67.Mn - Entanglement production, characterization, and manipulation.
03.65.Ud - Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.).
05.50.+q - Lattice theory and statistics (Ising, Potts, etc.).

© EDP Sciences 2006