Proposal for identifying possible even-parity superconducting states in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Sr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>RuO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math> using planar tunneling spectroscopy
Satoshi Ikegaya, Shu-Ichiro Suzuki, Yukio Tanaka, Dirk Manske
Abstract
After more than 25 years of research, three even-parity superconducting states-the d + id-wave, d + igwave, and s + id-wave states-have emerged as leading candidates for the superconducting states of Sr 2 RuO 4 . In the present work, we propose a tunneling spectroscopy experiment for distinguishing among these three superconducting states. The key component of our proposal is that we examine the conductance spectra of normal-metal/Sr 2 RuO 4 junctions with various angles between the junction interface and the crystal axis of the Sr 2 RuO 4 . The angle dependence of the conductance spectra shows a unique pattern in each superconducting state, which can function as a fingerprint for verifying the pairing symmetry of Sr 2 RuO 4 .