Giant persistent current in a quantum ring with multiple arms

We study theoretically the transmission coefficient and the persistent current in a new quantum ring with multiple arms. An equivalent method was developed and then applied to triple-arm open Aharonov-Bohm rings. The numerical results show that the persistent currents are different in each arm, which is quite different than the case of the single or coupled ring. The studies further show that the difference of the persistent current in the considered system with broken time-reversal symmetry is not caused by the magnetic flux but by the different states of electrons in each arm.