Nongeometric multiqubit conditional phase gates by adiabatic evolution for trapped ions

Abstract

We propose a scheme for realizing controlled multiqubit quantum phase gates via the adiabatic evolution for trapped ions. Leveraging on the adiabatic operation, the scheme is tolerant to ambient noise and insensitive to the randomness of moderate fluctuations in experimental parameters. In our scheme, the ions are illuminated by lasers tuned to the first lower vibrational sideband or quasiresonant transition, the vibrational mode is not utilized as a data bus, and dark state evolution is required. The required gate operation time does not increase with the increasing number of qubits. This leads to a more efficient implementation of multiqubit gates than that of a series of one-qubit and two-qubit operations for quantum circuits and quantum algorithms. © 2009 The American Physical Society.