All-resonant control of superconducting resonator qudits

Frederick W. Strauch, Xiaoting Wang, Kurt A. Jacobs

Hui Wang, Rui Wang, Daichi Sugiyama +5 more

Ignacio Gimeno, Fernando M. Luis, Carlos Marcuello +9 more

High Resolution Image Download MS PowerPoint Slide A strategy toward the realization of a quantum spin processor involves the coupling of spin qubits and qudits to photons within superconducting resonators. To enable the realization of such hybrid architecture, here we first explore the design of a chip with multiple lumped-element LC superconducting resonators optimized for their coupling to distinct transitions of a vanadyl porphyrin electronuclear qudit. The controlled integration of the vanadyl qudit onto the superconducting device, both in terms of number and orientation, is then attained using the in situ formation of nanosheets of a 2D framework built on the vanadyl qudit as a node. Low-temperature transmission experiments demonstrate the coupling of photons in resonators with different frequencies to the targeted electronuclear transitions of the vanadyl qudit, also confirming the control over the vanadyl qudit node orientation. The derived collective spin-photon couplings in the 0.3–1.6 MHz range then allow to estimate enhanced, optimal, single spin photon couplings up to 4 Hz.

Joel Strand

Frederick W. Strauch

An all-resonant method is proposed to control the quantum state of superconducting resonators. This approach uses a tunable artificial atom linearly coupled to resonators, and allows for efficient routes to Fock state synthesis, qudit logic operations, and synthesis of NOON states. This resonant approach is theoretically analyzed, and found to perform significantly better than existing proposals using the same technology.

Tauno Palomaki, Jennifer Harlow, Joseph Kerckhoff +4 more