Dresden 2003 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 14: Postersitzung III (Neue u. unkonventionelle Supraleiter, Anwendungen der Supraleitung, Dünne Schichten, JJs und SQUIDs, Schwere Fermionen, Kondo-Systeme)

TT 14.18: Poster

Mittwoch, 26. März 2003, 14:30–19:00, P2c

Decoherence and gate performance of coupled solid state qubits — •Markus J. Storcz und Frank K. Wilhelm — Sektion Physik und CeNS, Ludwig-Maximilians-Universität, Theresienstr. 37, 80333 München

Solid state quantum bits are promising candidates for the realization of a scalable quantum computer. However, they are usually strongly limited by decoherence due to the many degrees of freedom of a solid state system. We investigate a system of two coupled solid state qubits that are coupled via σ_z⁽¹⁾ ⊗ σ_z⁽²⁾ type of coupling. This kind of setup is typical for pseudospin solid-state quantum bits such as charge or flux systems. We evaluate decoherence properties and gate quality factors in the presence of a common and two uncorrelated baths coupling to σ_z, respectively. We show, that at low temperatures, uncorrelated baths do degrade the gate quality more severely. The type of coupling we invoke commutes with the coupling to the decoherence, which makes this type of coupling attractive as compared to previously studied proposals with σ_y⁽¹⁾ ⊗ σ_y⁽²⁾- coupling.

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