Research

Main Research Topics

Background & Motivation: How much energy does information processing cost? The second law of thermodynamics sets fundamental limits on all computation and information erasure. Our work focuses on finite-time thermodynamic bounds—understanding the trade-off between speed and energy efficiency in practical quantum systems.
What we do:
- Derive universal thermodynamic bounds on work cost for bit reset and information erasure in finite time
- Apply stochastic thermodynamics to quantum annealing and optimization algorithms
- Study the fundamental limits of energy-efficient quantum information processing
Goal: Establish rigorous thermodynamic constraints that guide the design of energy-efficient quantum computers and quantum communication protocols.
Key Results:
- Universal bound on energy cost of bit reset (Phys. Rev. Lett. 127, 190602, 2021)
- Thermodynamic limits to annealing performance (Phys. Rev. E 108, 054119, 2023)

Background & Motivation: Can we guarantee quantum key distribution security without trusting the quantum devices? Device-independent protocols achieve this through Bell inequality violations—proving security from quantum nonlocality alone. This is the strongest form of cryptographic security in the quantum regime.
What we do:
- Design and analyze device-independent QKD protocols based on nonlocal games (Bell tests)
- Develop protocols using magic square and Mermin-Peres games
- Study hybrid device-independent approaches combining MDI-QKD and DI-QKD
- Explore practical implementations over long-distance quantum networks
Goal: Bring device-independent quantum cryptography from fundamental physics to practical long-distance quantum networks—demonstrated over 100+ km with realistic devices.
Key Results:
- Device-independent QKD over 100 km with single atoms (Science 391, 592–597, 2026)
- DI-QKD via Mermin-Peres game (Phys. Rev. Lett. 131, 080801, 2023)
- Photonic DI-QKD demonstration (Phys. Rev. Lett. 129, 050502, 2022)

Background & Motivation: Quantum entanglement and nonlocality are not just philosophical curiosities—they are resources for cryptography, communication, and fundamental tests of quantum mechanics. Characterizing Bell nonlocality, quantum steering, and entanglement structure reveals deep insights into quantum reality.
What we do:
- Study Einstein-Podolsky-Rosen (EPR) steering and its certification methods
- Develop criteria for witnessing Bell nonlocality and entanglement-breaking channels
- Explore connections between nonlocality, steering, and their role in quantum protocols
- Certify quantum entanglement in experiments using self-testing and robust verification
Goal: Develop practical methods to certify nonlocality and steering in realistic experimental settings, supporting device-independent protocols.
Key Results:
- Steering certification via linear uncertainty principle (Phys. Rev. A 93, 012108, 2016)
- Non-local games and optimal steering (Phys. Rev. A 94, 022116, 2016)
- Robust self-testing in quantum networks (Phys. Rev. A 106, 042608, 2022)

Background & Motivation: Modern quantum technologies combine different physical platforms—superconducting qubits coupled to spin ensembles, trapped ions with optical cavities, quantum transducers bridging microwave and optical domains. Strong coupling in these hybrid systems enables new quantum information processing capabilities.
What we do:
- Investigate genuine strong-coupling regimes in superconducting-spin hybrids
- Study superradiance, quantum transduction, and entanglement generation in hybrid platforms
- Explore quantum repeater architectures with long-lived remote ion-ion entanglement
- Design hybrid protocols for distributed quantum computing and quantum networks
Goal: Realize scalable quantum repeaters and hybrid quantum networks combining different physical platforms.
Key Results:
- Strong coupling in a three-mode superconducting-spin hybrid quantum system (Phys. Rev. Research, 2026)
- Long-lived remote ion-ion entanglement for quantum repeaters (Nature, 2026)

For a full list of publications related to these topics, see the Works page.

Interested in collaboration? Feel free to reach out via email (listed in About).