Journal Article

Quantum control of surface acoustic-wave phonons

Schuster, D. I., Chou, Ming-Han, Satzinger, K. J., Bienfait, A., Zhong, Y. P., Cleland, A. Y., Gutierrez, I., Chang, H.-S., Peairs, G. A., Awschalom, D. D., Dumur, É., November, B. H., Cleland, A. N., Grebel, J., Povey, R. G., Conner, C. R., Whiteley, S. J.

2018

Overview

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 capability 1 , 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 state 3 – 7 . Here we demonstrate full quantum control of the mechanical state of a macroscale mechanical resonator. We strongly couple a surface acoustic-wave 8 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 tomography 9 – 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 systems 15 , 16 . A non-classical superposition of zero- and one-phonon mechanical Fock states is generated and measured by strongly coupling a surface acoustic-wave resonator to a superconducting qubit.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 142/126 / 639/766/483/1139 / 639/766/483/2802 / Acoustic waves / Analysis / Atoms / CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS / Experiments / Humanities and Social Sciences / Letter / Lithium / Mechanical systems / multidisciplinary / Phonons / Photons / Physics research / Quantum dots / Quantum mechanics / Quantum theory / Qubits (quantum computing) / Resonators / Science / Science (multidisciplinary) / Sound waves / Superconductors / Superposition (mathematics) / Surface acoustic waves / Tomography