Dissertation/Thesis Abstract

High frequency piezo-opto-mechanics for superconducting microwave and optical interface
by Han, Xu, Ph.D., Yale University, 2018, 168; 10957328
Abstract (Summary)

This thesis presents experimental investigation of high frequency piezo-opto-mechanics as an effective interface between superconducting microwave and photonic circuits, focusing on photon-phonon interactions within hybrid cavity electro-optomechanical systems. High frequency mechanical resonators subjected to low thermal phonon occupation are easier to be prepared to quantum ground state by direct cryogenic cooling. Phonons, which can be supported in mechanical resonators in the scale of optical wavelength but at microwave frequencies, are an excellent candidate for mediating microwave-optical photon interaction. In this thesis, we first demonstrate a high frequency piezo-optomechanical microdisk resonator by harnessing the acoustic thickness mode. Compared with the in-plane contour modes, the thickness mode can be easily engineered to high frequencies above 10 GHz with excellent mechanical and optical quality factors. Then, we constructed a triply resonant electro-optomechanical system at room temperature by integrating the optornechanical resonator with a half-lambda microstrip resonator. The resonantly enhanced electro-optomechanical transduction allows us to build a low-phase noise microwave source at X-band.

Next, we develop the electromechanical system at cryogenic temperatures, and demonstrate piezoelectric strong coupling between a superconducting microwave resonator and multiple modes of a bulk acoustic resonator oscillating at 10 GHz with a cooperativity exceeding 2 x 103. A high mechanical quality factor of 7.5 x 105 and a large frequency-quality factor product of 7.5 x 1015 Hz are obtained at 1.7 K. Interesting dynamics of classical temporal oscillations of the microwave energy is observed, implying the coherent conversion between phonons and photons. Furthermore, by exploiting the kinetic inductance, we demonstrate tunable nonlinear superconducting resonators. The frequency tunability provides a necessary solution for accurate frequency alignment in electro-optomechanical systems. The nonlinearity also offers us a great opportunity to realize parametric amplification, as well as coherent hybrid phononic comb generation in the multimode electromechanical cavity.

Finally, we propose an efficient hybrid microwave-optical interface consisting of a high frequency optomechanical cavity piezoelectrically coupled with a superconducting microwave resonator. The efficiency, bandwidth, and added noise of the coherent microwave-optical photon conversion are investigated theoretically. Based on these analyses, the device performance is significantly improved and optimized, and crucial experimental challenges including device integration, fiber-chip interfacing, and resonance alignment are successfully addressed. With these progresses, an efficient quantum-enabled microwave-optical interface can be expected in the near future.

In addition, this thesis also discusses the opportunity for entanglement generation between microwave and optical photons based on the high frequency electrooptomechanical interface. Two entanglement schemes, frequency entanglement and time-bin entanglement, are proposed with possible experimental configurations. The demonstrated high frequency cavity electro-optomechanics is compatible with superconducting quantum circuits and integrated photonics, representing an important step towards hybrid quantum systems.

Indexing (document details)
Advisor: Tang, Hong X.
School: Yale University
School Location: United States -- Connecticut
Source: DAI-B 79/12(E), Dissertation Abstracts International
Subjects: Applied physics, Engineering, Optics
Keywords: Comb, Hybrid Quantum System, Optomechanics, Piezo Electromechanics, Strong Coupling, Superconducting Qubits
Publication Number: 10957328
ISBN: 9780438273733
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