Band shift, band filling, and electron localization in a quantum wire detected via tunneling between parallel quantum wires

Quantum wires are building blocks of quantum devices, in which the phase of an electron wave function plays a fundamental role. Since electronic correlation in a quantum wire modifies or disturbs the Fermi wave vector of a single particle in a quantum wire, the detection of such correlation effects is an important issue in the field of quantum electronics. We report on the modification of the Fermi wave vector of a biased quantum wire due to the convolution of band filling and interaction-induced band shifting detected via tunneling between parallel quantum wires. We also show that the Fermi wave vector is no longer a good quantum number when the electron density is sufficiently low, which is consistent with the formation of a localized or Wigner-crystal-like state appearing when the electron correlation is dominant over the kinetic energy.