A Few Studies based on Circuit QED system with Triple-Leg Stripline Resonator

We have theoretically proposed a new circuit QED system implemented with a triple-leg stripline resonator (TSR). Unlikely from the LSR, the fundamental intra-cavity microwave modes of the TSR are two-fold degenerate. When a superconducting qubit is placed near one of the TSR legs, one fundamental mode is directly coupled to the qubit, while the other one remains uncoupled. Using our circuit QED system, we have theoretically studied a two-qubit quantum gate operation in a hybrid qubit composed of a flying microwave qubit and a superconducting qubit.

Conventional linear stripline resonators (LSR) have been used to build several interesting lattice structures including 2D Kagome and Lieb lattice. However, due to its structural limitations, it is hard to fabricate honeycomb lattice structures using the LSR. In contrast, our TSR can form an optical honeycomb lattice, since each resonator can be symmetrically connected to the three adjacent ones. We study the photonic honeycomb lattice nanoribbon, which exhibits a flat band, whose structure is complement to that of zigzag graphene nanoribbon in momentum space. By lateral coupling to qubits, we demonstrate that the dispersion of the edge states becomes linear and the slope of the linear dispersion is tunable by adjusting the coupling strength to the laterally placed qubits.