Magnetic Field Driven Quantum Phase Transitions in Josephson Arrays

J. Paramanandam; M. T. Bell; L. B. Ioffe; M. E. Gershenson

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arXiv · 1112.6377

Magnetic Field Driven Quantum Phase Transitions in Josephson Arrays

J. Paramanandam·M. T. Bell·L. B. Ioffe·M. E. Gershenson

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Abstract

We have studied the magnetic-field-driven quantum phase transitions in Josephson junction arrays with a large coordination number. The characteristic energies were extracted in both the superconducting and insulating phases by integrating the current-voltage characteristics over a voltage range 2eV\leqk_B T. For the arrays with a relatively strong Josephson coupling, we observed duality between the energies in the superconducting and insulating phases. The arrays with a weaker Josephson coupling demonstrate an intermediate, "bad metal" regime in weak magnetic fields; this observation underlines the importance of vortex pinning at large scales and, presumably, emergent inhomogeneity in the presence of strong offset charge disorder.

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J. Paramanandam, M. T. Bell, L. B. Ioffe, M. E. Gershenson. 2011-12-30. Magnetic Field Driven Quantum Phase Transitions in Josephson Arrays. https://arxiv.org/abs/1112.6377

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