Arbitrary state controlled-unitary gate by adiabatic passage

• Main Authors: Lacour, X, Sangouard, N, Guerin, S, Jauslin, H. R
• Format: Journal Article
• Language: English
• Published: 27-01-2006
• Subjects: Physics - Quantum Physics
• DOI: 10.48550/arxiv.quant-ph/0601183

Phys. Rev. A 73, 042321 (2006) We propose a robust scheme involving atoms fixed in an optical cavity to
directly implement the universal controlled-unitary gate. The present technique
based on adiabatic passage uses novel dark states well suited for the
controlled-rotation operation. We show that these dark states allow the robust
implementation of a gate that is a generalisation of the controlled-unitary
gate to the case where the control qubit can be selected to be an arbitrary
state. This gate has potential applications to the rapid implementation of
quantum algorithms such as of the projective measurement algorithm. This
process is decoherence-free since excited atomic states and cavity modes are
not populated during the dynamics.