Multiqubit tunable phase gate of one qubit simultaneously controlling n qubits in a cavity

Journal Article · Wed Dec 15 00:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.062326· OSTI ID:21528855

Chuiping, Yang ^[1]; Shibiao, Zheng ^[1]; Nori, Franco ^[1]

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1. Advanced Science Institute, RIKEN, Wako-Shi, Saitama 351-0198 (Japan)

We propose how to realize a multiqubit tunable phase gate of one qubit simultaneously controlling n qubits with four-level quantum systems in a cavity or coupled to a resonator. Each of the n two-qubit controlled-phase (cp) gates involved in this multiqubit phase gate has a shared control qubit but a different target qubit. In this proposal, the two lowest levels of each system represent the two logical states of a qubit while the two higher-energy intermediate levels are used for the gate implementation. The method presented here operates essentially by creating a single photon through the control qubit, which then induces a phase shift to the state of each target qubit. The phase shifts on each target qubit can be adjusted by changing the Rabi frequencies of the pulses applied to the target qubit systems. The operation time for the gate implementation is independent of the number of qubits, and neither adjustment of the qubit level spacings nor adjustment of the cavity mode frequency during the gate operation is required by this proposal. It is also noted that this approach can be applied to implement certain types of significant multiqubit phase gates (e.g., the multiqubit phase gate consisting of n two-qubit cp gates which are key elements in quantum Fourier transforms). A possible physical implementation of our approach is presented. Our proposal is quite general and can be applied to physical systems such as various types of superconducting devices coupled to a resonator and trapped atoms in a cavity.

• OSTI ID: 21528855
• Journal Information: Physical Review. A, Vol. 82, Issue 6; Other Information: DOI: 10.1103/PhysRevA.82.062326; (c) 2010 American Institute of Physics; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
CAVITY RESONATORS
CONTROL
FOURIER TRANSFORMATION
IMPLEMENTATION
PHASE SHIFT
PHOTONS
PROPOSALS
PULSES
QUBITS
SUPERCONDUCTING DEVICES
TRAPPING
BOSONS
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
EQUIPMENT
INFORMATION
INTEGRAL TRANSFORMATIONS
MASSLESS PARTICLES
QUANTUM INFORMATION
RESONATORS
TRANSFORMATIONS