Loss Mechanisms in Superconducting Quantum Transmission Line Metamaterials

Tamin Tai, Jingnan Cai, Steven M. Anlage

Jingnan Cai, Steven M. Anlage

R D Wilson, M. J. Everitt, Sergey E. Savel'ev +1 more

Quantum metamaterials consist of quantum coherent structures made up of artificial atoms connected by a transmission medium. In this work we investigate the effects of decoherence in both the transmission medium and the artificial atom using a fully quantum mechanical model. We consider a prototypical solid state 1D quantum metamaterial, i.e. a superconducting flux qubit coupled to a transmission line section on resonance. An initially excited qubit is found to effectively pump a propagating coherent pulse and increase the average output power of the transmission line. Evidence of entanglement between the qubit and the transmission line with a propagating coherent pulse is also demonstrated. This signature behaviour is found to still be evident when a level of decoherence in line with that found in typical experiments is introduced into the transmission line section as well as the qubit. Increasing levels of decoherence, particularly in the qubit, are shown to be dangerous as they destroy the quantum correlations between the qubit and the propagating field.

Matthew LaHaye

Hybrid quantum interconnects and processor components are likely to play an important role in future scalable quantum communication and computation networks. In this talk, I will outline several nascent ideas for a new type of hybrid system, composed of mechanical elements, superconducting metamaterials, and superconducting qubits, which could be applicable to quantum transduction and memory functions. Before introducing these new ideas, I will start with a summary of recent incipient work at Syracuse that has inspired them. My summary will include a brief overview of efforts in the LaHaye group to investigate interactions between a superconducting transmon qubit and UHF nanomechanical element1; as well, I will highlight work conducted concomitantly and independently by the Plourde group to study the mode structure2 and cQED interactions of a superconducting metamaterial transmission line. The talk will then conclude with an overview of related ideas to utilize qubit-coupled nanoresonator architectures as platforms for quantum simulation.

Alexandre M. Zagoskin

H. Wang, Alexander P. Zhuravel, S. Indrajeet +8 more

Multimode microwave resonators that can be strongly coupled to superconducting qubits allow exploration of large-scale entanglement, or quantum simulations of many-body phenomena. Typically, long superconducting transmission lines or large arrays of transmission-line resonators are required. This work demonstrates superconducting metamaterial resonators with a dense mode spectrum above a low-frequency band gap. Imaging of the microwave fields shows that these devices exhibit a left-handed dispersion relation, consistent with modeling and simulations. This compact design is compatible with superconducting-qubit integration for applications in quantum information and communication.