One of the hallmarks of quantum physics is the generation of non-classical quantum states and superpositions, which has been demonstrated in several quantum systems, including ions, solid-state qubits and photons. However, only indirect demonstrations of non-classical states have been achieved in mechanical systems, despite the scientific appeal and technical utility of such a capability1,2, including in quantum sensing, computation and communication applications. This is due in part to the highly linear response of most mechanical systems, which makes quantum operations difficult, as well as their characteristically low frequencies, which hinder access to the quantum ground state3,4,5,6,7. Here we demonstrate full quantum control of the mechanical state of a macroscale mechanical resonator. We strongly couple a surface acoustic-wave8 resonator to a superconducting qubit, using the qubit to control and measure quantum states in the mechanical resonator. We generate a non-classical superposition of the zero- and one-phonon Fock states and map this and other states using Wigner tomography9,10,11,12,13,14. Such precise, programmable quantum control is essential to a range of applications of surface acoustic waves in the quantum limit, including the coupling of disparate quantum systems15,16.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The datasets supporting this work are available from the corresponding author on request.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
We thank P. J. Duda, A. Dunsworth and D. Sank for discussions. Devices and experiments were supported by the Air Force Office of Scientific Research, the Army Research Laboratory and the Department of Energy (DOE). K.J.S. and S.J.W. were supported by the US National Science Foundation (NSF) GRFP (NSF DGE-1144085); É.D. was supported by LDRD funds from Argonne National Laboratory; A.N.C. and D.D.A. were supported by the DOE, Office of Basic Energy Sciences; and D.I.S. acknowledges support from the David and Lucile Packard Foundation. This work was partially supported by the UChicago MRSEC (NSF DMR-1420709) and made use of the Pritzker Nanofabrication Facility, which receives support from SHyNE, a node of the NSF’s National Nanotechnology Coordinated Infrastructure (NSF NNCI-1542205).
Nature thanks S. Deleglise and the other anonymous reviewer(s) for their contribution to the peer review of this work.