Measurement of two-qubit states by quantum point contacts
arXiv:cond-mat/0310293 · doi:10.1088/0953-8984/17/43/009
Abstract
We solve the master equations of two charged qubits measured by two serially coupled quantum point contacts (QPCs). We describe two-qubit dynamics by comparing entangled states with product states, and show that the QPC current can be used for reading out results of quantum calculations and providing evidences of two-qubit entanglement. We also calculate the concurrence of the two qubits as a function of dephasing rate that originates from the measurement. We conclude that coupled charge qubits can be effectively detected by a QPC-based detector.
10 pages, 8 figures. Full paper is prepared
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