Asymmetrical tunneling between similar metallic junctions with charge-density or spin-density waves: The case of broken symmetry

Tunneling current-voltage characteristics (CVC’s) are calculated for symmetrical junctions involving partially gapped metals with charge-density or spin-density waves. The possibility of opposite signs of the order parameter Σ’s in the electrodes is suggested. Then, despite the equality of |Σ|’s in both metals, the CVC’s are highly asymmetrical. The predicted phenomena comprise an example of the symmetry breaking in many-body systems. A qualitative agreement exists with the experimental CVC’s for point homocontacts URu₂Si₂URu₂Si₂.