Year: 1998
Type: article
Abstract: A model for a quantum register $\mathcal{R}$ made of $N$ replicas of a $d$-dimensional quantum system (cell) coupled with the environment is studied by means of a Born-Markov master equation (ME). Dissipation and decoherence are discussed in various cases in which a subdecoherent encoding can be rigorously found. For the quantum-bit case $(d=2)$ we have solved, for small $N,$ the ME by numerical direct integration and studied, as a function of the coherence length ${\ensuremath{\xi}}_{c}$ of the bath, fidelity and decoherence rates of states of the register. For large enough ${\ensuremath{\xi}}_{c}$ the singlet states of the global su(2) pseudo spin algebra of the register (noiseless at ${\ensuremath{\xi}}_{c}=\ensuremath{\infty})$ are shown to have a much smaller decoherence rates than the rest of the Hilbert space.
Source: Physical Review A
Author: Paolo Zanardi
Institutions: Institute for Scientific Interchange, Politecnico di Torino
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2018719845