Main research Projects
Exploring new physics beyond the Standard Model by precision measurements
Historically, most milestone experiments in fundamental and nuclear physics have been conducted at sprawling facilities like CERN, necessitating billions of dollars in investment, thousands of scientists and engineers, and more than a decade to establish. However, more recently, tabletop quantum technologies have also been demonstrated in fundamental and nuclear physics studies. For example, precision measurements of the electron’s Electric Dipole Moment (EDM) are some of the most successful low-energy tests. These have constrained the new physics beyond the leptonic sector of the Standard Model above the 10 TeV scale. Furthermore, atomic nuclei, composite particles comprising protons and neutrons and their constituent quarks and gluons, could create a fertile ground for investigating diverse symmetry-violating interactions in the hadronic sector of the Standard Model.However, the complex nuclear structure presents a significant challenge of having an unwieldy number of quantum states. An efficient quantum control scheme must be developed to drive the atomic populations into a single quantum state. Furthermore, different molecular species are required to disentangle convoluted interactions arising from the hadronic sector of the Standard Model.
To address these issues, we propose a novel experimental platform for achieving efficient preparation and detection , long coherence, and ubiquity for different molecular ions. The heart of our approach includes (1) implementing a quantum logic scheme to control heavy molecular ions, (2) designing new ion traps in a ring configuration, and (3) developing new precision metrology in a rapidly rotating frame. Based on this platform, we would be able to simultaneously investigate (1) charge and parity violations by probing the nuclear Magnetic Quadrupole Moment, (2) spin-dependent parity violations by measuring the nucleus anapole moment, and (3) the presence of the axion, a cold dark matter candidate.
Rydberg spectroscopy of RaF and BaF molecules
Radium monofluoride (RaF) has been widely recognized by theoretical physicists as an extraordinary candidate for probing parity and time-reversal violation effects. The incorporation of octupole-deformed radium isotopes in molecules significantly enhances the symmetry-violating nuclear moments, such as anapole and Schiff moments. RaF provides a unique opportunity to explore new physics beyond the Standard Model. We collaborate with Prof. Garcia-Ruiz at MIT, a leading expert in high-resolution spectroscopy of short-lived radioactive molecules. The collaboration aims to develop a new technique specifically designed to improve the spectroscopic resolution of RaF. This technique is expected to enable the precise discrimination of rovibronic and nuclear hyperfine structures, which are crucial in the precision measurements of the anapole and Schiff moments. Distinctly diverging from traditional spectroscopic methods that primarily focus on ground and low-lying states, the proposed approach centers on the structure and dynamics of highly excited electronic states - Rydberg states. These Rydberg states offer a novel methodological avenue, employing the outermost electron as a quantum sensor to intricately probe and elucidate the electronic and nuclear structures within the molecule. In addition to supporting fundamental physics studies, this cutting-edge technique holds the promise of yielding unprecedented insights and contributing significantly to our understanding of fundamental interactions in heavy element chemistry.
Collaborative research Projects
Hybrid quantum systems
Quantum information processing, including both quantum computation and quantum teleportation, promises to revolutionize the global information system with massively improved computation power, superior communication speed, and un-hackable security. Numerous international research groups in different disciplines are developing various architectures using photons, ions, neutral atoms, superconducting circuits, and optomechanical devices to achieve this goal. Trapped ion and superconducting circuit are the leading two architectures to date and have been semi-commercialized. The trapped ion quantum computer is advantageous in exhibiting quantum gates of high fidelity, long coherence times, and efficient remote entanglement and transportation. In contrast, the superconducting circuit quantum computer is superior in connecting many qubits and achieving fast quantum gate speeds. No single experimental platform has an overwhelming advantage as these systems are complementary in solving different problems. This proposal will integrate the two platforms that would present a significant step toward realizing the ultimate quantum computer with superior speed, scalability, and efficiency in long-distance teleportation.
Cold ion-radical chemistry
A major motivation for studying chemical reactions at low temperatures is to build a model that describes the evolution of interstellar matter. 150 different molecules (230 isotopologues) in the interstellar medium (ISM) have been identified. Molecular creation and evolution in cold environments (down to the cosmic background temperature, 2.73 K) reveals a rich and complex chemistry. A fundamental question is how such a variety of molecules, from the simplest molecule, hydrogen (H2), to large organic molecules, such as Polycyclic Aromatic Hydrocarbons (PAHs), can be produced and survive in harsh environments. Modern computer programs that incorporate abundant data from astronomy and spectroscopy are used to simulate the dynamical evolution of the universe. Although many mysteries related to the formation of the early universe have been solved by this method, there are still many inconsistencies between astronomical models and observations. A better understanding of fundamental chemical reactions is required to build more elaborate models. Chemical reactions in the universe are strongly constrained by the low temperature, which excludes ordinary chemical reactions that require significant activation energy. Thus, exothermic ion-radical reactions, typically without a significant activation barrier are considered to dominate the chemistry of cold interstellar matter. Our research focuses on studying state-controlled ion-radical reactions at low temperatures in a shuttling ion trap merged to a neutral molecular beam.
Developments and applications of optical frequency combs
Experimental control system - Process-oriented programing
Scalable quantum systems typically require many concurrently operating devices and dedicated data acquisition/processing to extract signals that would be hidden in noise sources. Unlike the sequential system, the order of concurrently executing procedures is determined at the run time. It is impractical to verify the validity of the control system by checking every state. Any unverified process could bury the signal or mimic artificial systematics. To solve this issue, we will collaborate with Prof. Pedersen's group in the computer science department to implement a novel process-oriented programming language - ProcessJ, specifically well-suited to concurrency. ProcessJ is a new language being invented and developed by Prof. Pedersen at UNLV; the basis for ProcessJ is the process algebra CSP, which means that programs written in ProcessJ can be model checked. This allows us, to a high degree of certainty, to verify that our control systems behave according to specifications. A control system can be made up of any number (even millions) of independent processes running concurrently and it can be proven free of unwanted behaviors. In addition, ProcessJ’s runtime system (the code that runs the code) is currently being proven to behave correctly, something no other standard programming-language has ever done before.