Tian Xie

All Publications

• Scalable microwave-to-optical transducers at the single-photon level with spins NATURE PHYSICS Xie, T., Fukumori, R., Li, J., Faraon, A. 2025

  View details for DOI 10.1038/s41567-025-02884-y

  View details for Web of Science ID 001472214300001

• Microwave-to-optical transduction with erbium ions coupled to planar photonic and superconducting resonators NATURE COMMUNICATIONS Rochman, J., Xie, T., Bartholomew, J. G., Schwab, K. C., Faraon, A. 2023; 14 (1): 1153

  Abstract

  Optical quantum networks can connect distant quantum processors to enable secure quantum communication and distributed quantum computing. Superconducting qubits are a leading technology for quantum information processing but cannot couple to long-distance optical networks without an efficient, coherent, and low noise interface between microwave and optical photons. Here, we demonstrate a microwave-to-optical transducer using an ensemble of erbium ions that is simultaneously coupled to a superconducting microwave resonator and a nanophotonic optical resonator. The coherent atomic transitions of the ions mediate the frequency conversion from microwave photons to optical photons and using photon counting we observed device conversion efficiency approaching 10-7. With pulsed operation at a low duty cycle, the device maintained a spin temperature below 100 mK and microwave resonator heating of less than 0.15 quanta.

  View details for DOI 10.1038/s41467-023-36799-0

  View details for Web of Science ID 000980806000023

  View details for PubMedID 36859486

  View details for PubMedCentralID PMC9977906

• Significant loophole-free test of Kochen-Specker contextuality using two species of atomic ions SCIENCE ADVANCES Wang, P., Zhang, J., Luan, C., Um, M., Wang, Y., Qiao, M., Xie, T., Zhang, J., Cabello, A., Kim, K. 2022; 8 (6): eabk1660

  Abstract

  Quantum measurements cannot be thought of as revealing preexisting results, even when they do not disturb any other measurement in the same trial. This feature is called contextuality and is crucial for the quantum advantage in computing. Here, we report the observation of quantum contextuality simultaneously free of the detection, sharpness, and compatibility loopholes. The detection and sharpness loopholes are closed by adopting a hybrid two-ion system and highly efficient fluorescence measurements offering a detection efficiency of 100% and a measurement repeatability of >98%. The compatibility loophole is closed by targeting correlations between observables for two different ions in a Paul trap, a 171Yb+ ion and a 138Ba+ ion, chosen so measurements on each ion use different operation laser wavelengths, fluorescence wavelengths, and detectors. The experimental results show a violation of the bound for the most adversarial noncontextual models and open a way to certify quantum systems.

  View details for DOI 10.1126/sciadv.abk1660

  View details for Web of Science ID 000753670300005

  View details for PubMedID 35138888

  View details for PubMedCentralID PMC8827658

• Characterization of Er<SUP>3+</SUP>:YVO₄ for microwave to optical transduction PHYSICAL REVIEW B Xie, T., Rochman, J., Bartholomew, J. G., Ruskuc, A., Kindem, J. M., Craiciu, I., Thiel, C. W., Cone, R. L., Faraon, A. 2021; 104 (5)

  View details for DOI 10.1103/PhysRevB.104.054111

  View details for Web of Science ID 000686908700001

• On-chip coherent microwave-to-optical transduction mediated by ytterbium in YVO₄ NATURE COMMUNICATIONS Bartholomew, J. G., Rochman, J., Xie, T., Kindem, J. M., Ruskuc, A., Craiciu, I., Lei, M., Faraon, A. 2020; 11 (1): 3266

  Abstract

  Optical networks that distribute entanglement among various quantum systems will form a powerful framework for quantum science but are yet to interface with leading quantum hardware such as superconducting qubits. Consequently, these systems remain isolated because microwave links at room temperature are noisy and lossy. Building long distance connectivity requires interfaces that map quantum information between microwave and optical fields. While preliminary microwave-to-optical transducers have been realized, developing efficient, low-noise devices that match superconducting qubit frequencies (gigahertz) and bandwidths (10 kilohertz - 1 megahertz) remains a challenge. Here we demonstrate a proof-of-concept on-chip transducer using trivalent ytterbium-171 ions in yttrium orthovanadate coupled to a nanophotonic waveguide and a microwave transmission line. The device's miniaturization, material, and zero-magnetic-field operation are important advances for rare-earth ion magneto-optical devices. Further integration with high quality factor microwave and optical resonators will enable efficient transduction and create opportunities toward multi-platform quantum networks.

  View details for DOI 10.1038/s41467-020-16996-x

  View details for Web of Science ID 000546312300004

  View details for PubMedID 32601274

  View details for PubMedCentralID PMC7324619

• Frequency stabilization of a 650 nm laser to an I₂ spectrum for trapped <SUP>138</SUP>Ba<SUP>+</SUP> ions JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS Xie, T., Jin, N., Wang, Y., Zhang, J., Um, M., Wang, P., Kim, K. 2019; 36 (2): 243-247

  View details for DOI 10.1364/JOSAB.36.000243

  View details for Web of Science ID 000457457000041