Pairing of Cooper pairs in a fully frustrated Josephson-junction chain.
We study a one-dimensional Josephson-junction chain embedded in a magnetic field. We show that, when the magnetic flux per elementary loop equals half the superconducting flux quantum phi0 = h/2e, a local Z2 symmetry arises. This symmetry is responsible for a nematic Luttinger liquid state associated with bound states of Cooper pairs. We analyze the phase diagram and discuss some experimental possibilities to observe this exotic phase.
Douçot
Benoit
B
Laboratoire de Physique de la Matière Condensée, CNRS UMR 8551, Ecole Normale Supérieure, 24, rue Lhomond, 75231 Paris Cedex 05, France.
Vidal
Julien
J