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arXiv · 1304.1749

Sensitivity of the decay of entanglement of quantum dot spin qubits to the magnetic field

Paweł Mazurek·Katarzyna Roszak·Ravindra W. Chhajlany·Paweł Horodecki
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Abstract

We study the decay of entanglement of quantum dot electron-spin qubits under hyperfine interaction mediated decoherence. We show that two qubit entanglement of a single entangled initial state may exhibit decay characteristic of the two disentanglement regimes in a single sample, when the external magnetic field is changed. The transition is manifested by the supression of time-dependent entanglement oscillations which are superimposed on the slowly varying entanglement decay related to phase decoherence (which result in oscillatory behaviour of entanglement sudden death time as a function of the magnetic field). This unique behaviour allows us to propose the double quantum dot two-electron spin Bell state as a promising candidate for precise measurements of the magnetic field.

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Paweł Mazurek, Katarzyna Roszak, Ravindra W. Chhajlany, Paweł Horodecki. 2013-09-12. Sensitivity of the decay of entanglement of quantum dot spin qubits to the magnetic field. https://doi.org/10.1103/physreva.89.062318

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