Cooper-Pair Box Coupled to Two Resonators: An Architecture for a Quantum Refrigerator

Superconducting circuits present a promising platform with which to realize a\nquantum refrigerator. Motivated by this, we fabricate and perform spectroscopy\nof a gated Cooper-pair box, capacitively coupled to two superconducting\ncoplanar waveguide resonators with different frequencies. We experimentally\ndemonstrate the strong coupling of a charge qubit to two superconducting\nresonators, with the ability to perform voltage driving of the qubit at GHz\nfrequencies. We go on to discuss how the measured device could be modified to\noperate as a cyclic quantum refrigerator by terminating the resonators with\nnormal-metal resistors acting as heat baths.\n