Quantum gate in the decoherence-free subspace of trapped-ion qubits
Institut für Physik, Johannes Gutenberg-Universität Mainz - 55099 Mainz, Germany, EU
2 Department of Physics, Sofia University - James Bourchier 5 blvd, 1164 Sofia, Bulgaria, EU
Accepted: 20 October 2010
We propose a geometric phase gate in a decoherence-free subspace with trapped ions. The quantum information is encoded in the Zeeman sublevels of the ground state and two physical qubits to make up one logical qubit with ultra-long coherence time. Single- and two-qubit operations together with the transport and splitting of linear ion crystals allow for a robust and decoherence-free scalable quantum processor. For the ease of the phase gate realization we employ one Raman laser field on four ions simultaneously, i.e. no tight focus for addressing. The decoherence-free subspace is left neither during gate operations nor during the transport of quantum information.
PACS: 03.67.Lx – Quantum computation architectures and implementations / 37.10.Ty – Ion trapping / 32.80.Qk – Coherent control of atomic interactions with photons
© EPLA, 2010