Protecting two-qubit quantum states by<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>π</mml:mi></mml:mrow></mml:math>-phase pulses

Abstract

We study the state decay of two qubits interacting with a common harmonic oscillator reservoir. We find both a decoherence error and the error caused by the amplitude change of the superradiant state. We show that frequent $\ensuremath{\pi}$-phase pulses can eliminate both types of errors and therefore protect a two-qubit odd-parity state more effectively than the frequent measurement method. This shows that the methods using dynamical decoupling and the quantum Zeno effects actually can give rather different results when the operation frequency is finite.

Locations

• Physical Review A - View
• arXiv (Cornell University) - View - PDF
• DataCite API - View