Tunable coupling between three qubits as a building block for a superconducting quantum computer

Abstract

Large scale quantum computers will consist of many interacting qubits. In this paper we expand the two flux qubit coupling scheme first devised in [Phys. Rev. B {\bf 70}, 140501 (2004)] and realized in [Science {\bf 314}, 1427 (2006)] to a three-qubit, two-coupler scenario. We study L-shaped and line-shaped coupler geometries, and show how the interaction strength between qubits changes in terms of the couplers' dimensions. We explore two cases: the "on-state" where the interaction energy between two nearest-neighbor qubits is high, and the "off-state" where it is turned off. In both situations we study the undesirable crosstalk with the third qubit. Finally, we use the GRAPE algorithm to find efficient pulse sequences for two-qubit gates subject to our calculated physical constraints on the coupling strength.

8 pages, 7 figures, published version

References in corpus (13)

• Superconducting Circuits and Quantum Information
• Fault-tolerant quantum computation with high threshold in two dimensions
• Quantum computing with nearest neighbor interactions and error rates over 1%
• Controllable coupling of superconducting flux qubits
• Tuning the Gap of a Superconducting Flux Qubit
• High-contrast dispersive readout of a superconducting flux qubit using a nonlinear resonator
• Interqubit coupling mediated by a high-excitation-energy quantum object
• Mediated tunable coupling of flux qubits
• Coherent oscillations in a superconducting tunable flux qubit manipulated without microwaves
• Long-range coupling and scalable architecture for superconducting flux qubits
• Analysis of a tuneable coupler for superconducting phase qubits
• Tuned transition from quantum to classical for macroscopic quantum states
• Tunable coupling of qubits: nonadiabatic corrections

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