Interqubit coupling mediated by a high-excitation-energy quantum object

Sahel Ashhab, A. O. Niskanen, K. Harrabi, Y. Nakamura, T. Picot, P. C. De Groot, C. J P M Harmans, J. E. Mooij, Franco Nori

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

We consider a system composed of two qubits and a high excitation energy quantum object used to mediate coupling between the qubits. We treat the entire system quantum mechanically and analyze the properties of the eigenvalues and eigenstates of the total Hamiltonian. After reproducing well-known results concerning the leading term in the mediated coupling, we obtain an expression for the residual coupling between the qubits in the off state. We also analyze the entanglement between the three objects, i.e., the two qubits and the coupler, in the eigenstates of the total Hamiltonian. Although we focus on the application of our results to the recently realized parametric-coupling scheme with two qubits, we also discuss extensions of our results to harmonic-oscillator couplers, couplers that are near resonance with the qubits and multiqubit systems. In particular, we find that certain errors that are absent for a two-qubit system arise when dealing with multiqubit systems.

Original languageEnglish
Article number014510
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number1
DOIs
Publication statusPublished - 17 Jan 2008
Externally publishedYes

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Hamiltonians
Excitation energy
couplers
excitation
eigenvectors
energy
harmonic oscillators
eigenvalues

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Interqubit coupling mediated by a high-excitation-energy quantum object. / Ashhab, Sahel; Niskanen, A. O.; Harrabi, K.; Nakamura, Y.; Picot, T.; De Groot, P. C.; Harmans, C. J P M; Mooij, J. E.; Nori, Franco.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 77, No. 1, 014510, 17.01.2008.

Research output: Contribution to journalArticle

Ashhab, S, Niskanen, AO, Harrabi, K, Nakamura, Y, Picot, T, De Groot, PC, Harmans, CJPM, Mooij, JE & Nori, F 2008, 'Interqubit coupling mediated by a high-excitation-energy quantum object', Physical Review B - Condensed Matter and Materials Physics, vol. 77, no. 1, 014510. https://doi.org/10.1103/PhysRevB.77.014510
Ashhab, Sahel ; Niskanen, A. O. ; Harrabi, K. ; Nakamura, Y. ; Picot, T. ; De Groot, P. C. ; Harmans, C. J P M ; Mooij, J. E. ; Nori, Franco. / Interqubit coupling mediated by a high-excitation-energy quantum object. In: Physical Review B - Condensed Matter and Materials Physics. 2008 ; Vol. 77, No. 1.
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