Novel Insulator to Metal Transition and Superconductivity in Sr-doped La2CuO4
نویسندگان
چکیده
We have studied the charge dynamics of Sr-doped La2CuO4 at hole concentration p = 0.07. We observed a clear indication of the competition between two Wigner lattice orders: One corresponds to a Tc = 15 K superconductivity and the other to Tc = 30K. Our results naturally explain the recent observation of metallic transport in extremely low (1%) Sr-doped La2CuO4 and establish a novel insulator to metal transition mechanism and superconductivity in the 2D Wigner lattice ground state. We suggest that the fluctuations of the relative phase between the superconducting condensate and the Wigner lattice order account for the recent observation of the transverse Josephson plasmon mode. PACS Number: 78.30.Er 72.15.-v 74.25.Fy 74.72.Jt
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