Light-Matter Interaction: Multi-Emitter Cavity QED, Squeezed Light Driving of Cavity QED Systems, Free Electron - Solid State Spins

Squeezed Light Driving of Cavity QED Systems

We are passionate about exploring the world of nonlinear quantum optics and integrated photonics, where new developments in nanofabrication are harnessed to unlock new possibilities in quantum technology and science. Our work spans from the theoretical foundations of quantum optics to the practical development of advanced photonic systems. 

We believe that nanofabricated photonic devices are the key to useful scalable quantum technology. We’re particularly focused on understanding how light behaves in micro-resonators—tiny structures that can trap light efficiently and enhance light-matter interactions on-chip. These systems exhibit rich nonlinear dynamics, where light can self-organize into patterns and pulses.

Figure 1 (a) Self emerging pulses generating quantum light (blue is classical light and red is quantum.  (b,c) Spectrum of classical soliton (top) and soliton crystal  generating quantum light (bottom).  

Our research involves studying the quantum light generated on these systems by nonlinear optical processes. Our work seeks to unravel the dynamics to better understand how quantum light can be controlled for applications in quantum communication, computing, and sensing. Utilizing 4H-Silicon Carbide resonators, allows us to explore also the intersection of nonlinear optics, and quantum emitters, mixing macroscopic quantum photonic phenomena (Continuous variable approach) with discrete quantum optics. 

Figure 2: (a) Tunable nonlinear micro-resonators(4H-SiC) fabricated by our group at Stanford (b) Generating complex network behavior of quantum light -  multifrequency light (red) is generating a network of quantum light (green).

References:

M.A. Guidry, D.M. Lukin, , K.Y. Yang, et al. Quantum optics of soliton microcombs. Nat. Photon. 16, 52–58 (2022)

M. A. Guidry, D. M. Lukin, K. Y. Yang, and J. Vučković, "Multimode squeezing in soliton crystal microcombs," Optica 10, 694-701 (2023)

E. Lustig, M. A. Guidry, D. M. Lukin, S. Fan, and J. Vuckovic, Emerging Quadrature Lattices of Kerr Combs, arXiv:2407.13049. (2024)

Free Electron Light Interactions in Nanophotonics

The Vučković group aims to explore recent advances that all rely on the fundamental interactions between free electrons and light in nanophotonics and integrated photonics platforms. Such interactions revealed in recent years novel physics that has led to the emergence of the new field of free-electron quantum optics. The free electron is now becoming a new quantum particle, filling the role traditionally kept for atoms and molecules or quantum dots. Being characterized by a continuum of energy levels, rather than a discrete set, electron-light interactions are unique in several aspects such as high degree of spectral tunability, ultrafast operation times as well as compatibility with several quantum optical information processing paradigms.

Our research in this field is articulated along two main threads:

1. Accelerators on a chip

The ACHIP project seeks to revolutionize electron accelerators by replacing conventional radio-frequency systems with optical and near-infrared sources, dramatically reducing their size. This could potentially shrink large accelerators like SLAC's kilometer-scale accelerator into a shoebox-sized device. However, due to high losses in metals at optical frequencies, the accelerator components must be redesigned using dielectric materials such as silicon. The Vuckovic Lab contributes to this effort by employing inverse design techniques to create waveguide-integrated accelerators (see Figure 2a). These designs optimize the coupling, splitting, and phase-tuning of light from fiber lasers to the accelerator structure, ensuring efficient performance while maintaining fabricability and minimizing unwanted fields.

2. Interactions between free electrons and solid state qubits 

The interaction of light with molecular and atomic systems underpins a wide array of fundamental physical effects and emerging quantum technologies. A paradigm in light-matter interactions is the Jaynes-Cummings Hamiltonian which describes the coupling of a single two-level system (TLS) with quantized modes of the electromagnetic fields. 

Recently, it was proposed that TLS could instead be driven by the electromagnetic field carried by electron beams, an effect coined “free-electron bound-electron resonant interaction” (FEBERI). In addition to exhibiting the fundamental effects known in conventional light-matter interactions (such as Rabi oscillations), FEBERI provides an exciting route towards nanoscale control of quantum systems, electron microscopy methods to image the coherence of matter, and generation of entangled quantum states. Our group is developing the first platform to explore these new effects in quantum optics with free electrons (see Figure 2b).

References:N. V. Sapra, K. Y. Yang, D. Vercruysse, K. J. Leedle, D. S. Black, R. J. England, L. Su, R. Trivedi, Y. Miao, and O. Solgaard, R. L. Byer, J. Vučković, "On-chip integrated laser-driven particle accelerator," Science 367, 79-83 (2020)D. Catanzaro, Y. Grzesik, C. Roques-Carmes, K. Leedle, D. Black, O. Solgaard, J. Vučković. “An Experimental Platform to Control Solid-State Spin Systems with Engineered Electron Beams”. In CLEO: QELS_Fundamental Science; Optica Publishing Group, 2024; p FM4F.5.