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arXiv · 1308.1407

Quantum phase transitions out of a Z2 x Z2 topological phase

Saeed S. Jahromi·S Farhad Masoudi·Mehdi Kargarian·Kai Phillip Schmidt
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Abstract

We investigate the low-energy spectral properties and robustness of the topological phase of color code, which is a quantum spin model for the aim of fault-tolerant quantum computation, in the presence of a uniform magnetic field or Ising interactions, using high-order series expansion and exact diagonalization. In a uniform magnetic field, we find 1st-order phase transitions in all field directions. In contrast, our results for the Ising interactions unveil that for strong enough Ising couplings, the Z2 x Z2 topological phase of color code breaks down to symmetry broken phases by 1st- or 2nd-order phase transitions.

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Saeed S. Jahromi, S Farhad Masoudi, Mehdi Kargarian, Kai Phillip Schmidt. 2013-12-12. Quantum phase transitions out of a Z2 x Z2 topological phase. https://doi.org/10.1103/physrevb.88.214411

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