Experimentally simulating the dynamics of quantum light and matter at deep-strong coupling. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Langford, N.; Sagastizabal, R.; Kounalakis, M.; Dickel, C.; Bruno, A.; Luthi, F.; Thoen, D.; Endo, A.; DiCarlo, L.
• Is Part Of: Nature communications. Volume 8:Issue 1(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-12
• Subjects: Biology -- Periodicals; Physical sciences -- Periodicals; 505
• DOI: 10.1038/s41467-017-01061-x
• Languages: English
• ISSNs: 2041-1723

Abstract

Abstract The quantum Rabi model describing the fundamental interaction between light and matter is a cornerstone of quantum physics. It predicts exotic phenomena like quantum phase transitions and ground-state entanglement in ultrastrong and deep-strong coupling regimes, where coupling strengths are comparable to or larger than subsystem energies. Demonstrating dynamics remains an outstanding challenge, the few experiments reaching these regimes being limited to spectroscopy. Here, we employ a circuit quantum electrodynamics chip with moderate coupling between a resonator and transmon qubit to realise accurate digital quantum simulation of deep-strong coupling dynamics. We advance the state of the art in solid-state digital quantum simulation by using up to 90 second-order Trotter steps and probing both subsystems in a combined Hilbert space dimension of ∼80, demonstrating characteristic Schrödinger-cat-like entanglement and large photon build-up. Our approach will enable exploration of extreme coupling regimes and quantum phase transitions, and demonstrates a clear first step towards larger complexities such as in the Dicke model. Realising deep-strong coupling phenomena for interacting light-matter systems remains an experimental challenge. Here, Langford et al. employ a circuit quantum electrodynamics chip with moderate coupling between a resonator and transmon qubit to realise digital quantum simulation of deep-strong coupling dynamics.