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arXiv · 0910.1750

Decoherence in a dynamical quantum phase transition

Sarah Mostame·Gernot Schaller·Ralf Schützhold
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Abstract

Motivated by the similarity between adiabatic quantum algorithms and quantum phase transitions, we study the impact of decoherence on the sweep through a second-order quantum phase transition for the prototypical example of the Ising chain in a transverse field and compare it to the adiabatic version of Grovers search algorithm, which displays a first order quantum phase transition. For site-independent and site-dependent coupling strengths as well as different operator couplings, the results show that (in contrast to first-order transitions) the impact of decoherence caused by a weak coupling to a rather general environment increases with system size (i.e., number of spins/qubits). This might limit the scalability of the corresponding adiabatic quantum algorithm.

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Sarah Mostame, Gernot Schaller, Ralf Schützhold. 2010-04-15. Decoherence in a dynamical quantum phase transition. https://doi.org/10.1103/physreva.81.032305

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