Subharmonic Shapiro Steps and Assisted Tunneling in Superconducting Point Contacts
Subharmonic Shapiro Steps and Assisted Tunneling in Superconducting Point Contacts
We analyze the current in a superconducting point contact of arbitrary transmission in the presence of a microwave radiation. The interplay between the ac Josephson current and the microwave signal gives rise to Shapiro steps at voltages V = (m/n)h(omega)(r)/2e, where n,m are integer numbers and omega(r) is the radiation …