Quantum sensing with qubits has advanced fundamental physics searches, but higher dimensional systems offer untapped potential. We present a universal qutrit framework that yields a sequence-independent fourfold increase in quantum Fisher information and a twofold gain in sensitivity. In ultralight dark matter searches, spin-1 NV-center qutrits can enhance the axion-electron coupling reach by an order of magnitude beyond qubits. This principle applies broadly to multilevel quantum systems including superconducting, neutral atom and trapped-ion qutrits, establishing higher dimensional sensing as a powerful tool for probing new physics.
Quantum sensing with qubits has advanced fundamental physics searches, but higher dimensional systems offer untapped potential. We present a universal qutrit framework that yields a sequence-independent fourfold increase in quantum Fisher information and a twofold gain in sensitivity. In ultralight dark matter searches, spin-1 NV-center qutrits can enhance the axion-electron coupling reach by an order of magnitude beyond qubits. This principle applies broadly to multilevel quantum systems including superconducting, neutral atom and trapped-ion qutrits, establishing higher dimensional sensing as a powerful tool for probing new physics.
One of the areas of research of the Superconducting Quantum Systems and Materials (SQMS) center is the application of quantum sensing to fundamental physics searches, demonstrating that quantum sensors can greatly improve the sensitivity of experiments searching for Beyond the Standard Model (BSM) physics, or performing high-precision measurements. Theorists have developed many ideas for BSM physics that would result in interactions that can in principle be detected, but with signals small enough that they haven t been observed yet. In this field, the capability to lower the detector s thermal noise to few or dozens of mK, and to use QIS technologies such as Josephson Parametric Amplifiers and photon counters (in-situ or itinerant) enable us to reach unprecedented sensitivities and faster scan rates. Here is presented an overview of the quantum sensing efforts at SQMS [1], focusing on theoretical advancements and experimental searches for Dark Sector particles (as dark matter candidates and not), gravitational waves, and precision measurements. The experiments conducted, or under preparation, include axion dark matter (DM) [2, 3], dark photon DM searches [4,5], light-shining-through-wall experiments [6], cavity-based searches for high frequency gravitational waves [7], and measurements of the electron magnetic moment [8]. [1] Berlin, A., et al. "Searches for new particles, dark matter, and gravitational waves with SRF cavities." arXiv preprint arXiv:2203.12714 (2022). [2] Giaccone, B., et al. "Design of axion and axion dark matter searches based on ultra high Q SRF cavities." arXiv preprint arXiv:2207.11346 (2022). [3] Braggio, C., et al. "Quantum-enhanced sensing of axion dark matter with a transmon-based single microwave photon counter." arXiv preprint arXiv:2403.02321 (2024). [4] Fan, X., et al. "One-electron quantum cyclotron as a milli-eV dark-photon detector." Physical review letters 129.26 (2022): 261801. [5] Cervantes, R., et al. "Deepest sensitivity to wavelike dark photon dark matter with superconducting radio frequency cavities." Physical Review D 110.4 (2024): 043022. [6] Romanenko, A., et al. "Search for dark photons with superconducting radio frequency cavities." Physical review letters 130.26 (2023): 261801. [7] Berlin, A., et al. "Electromagnetic cavities as mechanical bars for gravitational waves." Physical Review D 108.8 (2023): 084058. [8] Fan, X., et al. "Measurement of the electron magnetic moment." Physical review letters 130.7 (2023): 071801.
Recent advancements in space science and technologies offer exciting prospects for investigating novel research that is unattainable within terrestrial laboratories. Here we propose the implementation of space-based quantum sensing to explore ultralight new particles beyond the standard model. The central idea involves probing long-range interactions between spin ensembles of space quantum sensors and the particles residing within Earth, mediated by ultralight particles. We show that such interactions can be substantially enhanced in space platforms and thus increase the search sensitivity. In contrast to their terrestrial counterparts, space-based quantum searches exhibit remarkable velocity enhancements, approaching the first cosmic speed, and thus enables the exploration of unexplored parameter space concerning ultralight new particles. Furthermore, the substantial abundance of electrons and nucleons within Earth plays a crucial role in extending the scope of our mission. Our projected search sensitivity can surpass the sensitivities of both terrestrial experiments and proposals by up to approximately 7 orders of magnitude. We also briefly discuss other space mission, including ``space-ground integrated" network of quantum sensors for dark matter searches.
Quantum sensing is a rapidly growing approach to probe fundamental physics and explore new phase space for possible new physics with precision and highly sensitive measurements in our quest to understand the deep structure of matter and its interactions. This field uses properties of quantum mechanics in the detectors to go beyond traditional measurement techniques. Key particle physics topics where quantum sensing can play a vital role include neutrino properties, tests of fundamental symmetries (Lorentz invariance and the equivalence principle as well as searches for electric dipole moments and possible variations in fundamental constants), the search for dark matter and testing ideas about the nature of dark energy. Interesting new sensor technologies include atom interferometry, optomechanical devices, and atomic and nuclear clocks including with entanglement. This Perspective explores the opportunities for these technologies in future particle physics experiments, opening new windows on the structure of the Universe.
The applications of spin-based quantum sensors to measurements probing fundamental physics are surveyed. Experimental methods and technologies developed for quantum information science have rapidly advanced in recent years, and these tools enable increasingly precise control and measurement of spin dynamics. Theories of beyond-the-Standard-Model physics predict, for example, symmetry violating electromagnetic moments aligned with particle spins, exotic spin-dependent forces, coupling of spins to ultralight bosonic dark matter fields, and changes to the local environment that affect spins. Spin-based quantum sensors can be used to search for these myriad phenomena, and offer a methodology for tests of fundamental physics that is complementary to particle colliders and large scale particle detectors. Areas of technological development that can significantly enhance the sensitivity of spin-based quantum sensors to new physics are highlighted.
An introductory review is provided for those who are interested in exploring applications of qubits and other quantum excitations to the detection of dark matter (and any other physics beyond the Standard Model). Topics covered include the fundamental properties of qubits, the excitation mechanism of qubits due to the electric field induced by dark matter (with attention to the effects of the coherence of dark matter), the dynamics of coupled qubit-cavity systems modeled by the Jaynes-Cummings framework, and the influence of noise and decoherence (especially Markovian noise described by the Lindblad equation). In addition, the article introduces essential concepts in quantum sensing, including the operator-sum representation and positive operator-valued measures, the Cramér-Rao bound, the standard quantum limit and the Heisenberg limit, and the potential enhancement of sensitivity to dark matter achievable with entangled states. Throughout, these topics are discussed with particular emphasis on their application to the detection of wave-like dark matter.