Jian-Wei Pan

Jian-Wei Pan, born on 11 March 1970, received his Bachelor (1992) and Master (1995) in Physics from the University of Science and Technology of China, Hefei, and his PhD (1999) from the University of Vienna. He is currently a Professor of Physics at the University of Science and Technology of China, an Academician of Chinese Academy of Sciences (CAS), a Fellow of the World Academy of Sciences (TWAS) and a foreign member of the Royal Society (London). He serves as the Director of the CAS Center for Excellence in Quantum Information and Quantum Physics. Prof. Jian-Wei Pan’s research fields focus on quantum foundations, quantum optics and quantum information. Pan pioneers in multi-particle interferometry and quantum experiments in space. He closed major loopholes for secure quantum communication associated with imperfect devices, making it a viable technology under realistic conditions. His group developed the quantum satellite Micius, demonstrated the first intercontinental quantum communication. These pioneering efforts bring global-scale secure quantum communication from a purely theoretical concept to reality. His group demonstrated quantum computational advantage, validating the feasibility of quantum computing systems to outperform classical machines in solving specific problems. He has also conducted a series of studies in quantum simulation with ultracold gas, including research on synthetic gauge potentials, atom-atom entanglement, ultracold molecular chemistry, and quantum simulation of the Fermi-Hubbard model.

Quantum key distribution is a cornerstone of quantum technology, offering information-theoretical secure keys for remote parties. With many quantum communication networks established globally, the mode-pairing protocol stands out for its efficacy over inter-city distances using simple setups, emerging as a promising solution. In this study, we employ the mode-pairing scheme into existing inter-city fiber links, conducting field tests across distances ranging from tens to about a hundred kilometers. Our system achieves a key rate of $1.217$ kbit/s in a $195.85$ km symmetric link and $3.089$ kbit/s in a $127.92$ km asymmetric link without global phase locking. The results demonstrate that the mode-pairing protocol can achieve key rates comparable to those of a single quantum link between two trusted nodes on the Beijing-Shanghai backbone line, effectively reducing the need for half of the trusted nodes. These field tests confirm the mode-pairing scheme's adaptability, efficiency, and practicality, positioning it as a highly suitable protocol for quantum networks.

Quantum key distribution (QKD) theoretically provides unconditional security between remote parties. However, guaranteeing practical security through device characterisation alone is challenging in real-world implementations due to the multi-dimensional spaces in which the devices may be operated. The side-channel-secure (SCS)-QKD protocol, which only requires bounding the upper limits of the intensities for the two states, theoretically provides a rigorous solution to the challenge and achieves measurement-device-independent security in detection and security for whatever multi-dimensional side channel attack in the source. Here, we demonstrate a practical implementation of SCS-QKD, achieving a secure key rate of 6.60 kbps through a 50.5 km fibre and a maximum distribution distance of 101.1 km while accounting for finite-size effects. Our experiment also represents an approximate forty-times improvement over the previous experiment.

Quantum money is the first invention in quantum information science, promising advantages over classical money by simultaneously achieving unforgeability, user privacy, and instant validation. However, standard quantum money relies on quantum memories and long-distance quantum communication, which are technologically extremely challenging. Quantum "S-money" tokens eliminate these technological requirements while preserving unforgeability, user privacy, and instant validation. Here, we report the first full experimental demonstration of quantum S-tokens, proven secure despite errors, losses and experimental imperfections. The heralded single-photon source with a high system efficiency of 88.24% protects against arbitrary multi-photon attacks arising from losses in the quantum token generation. Following short-range quantum communication, the token is stored, transacted, and verified using classical bits. We demonstrate a transaction time advantage over intra-city 2.77 km and inter-city 60.54 km optical fibre networks, compared with optimal classical cross-checking schemes. Our implementation demonstrates the practicality of quantum S-tokens for applications requiring high security, privacy and minimal transaction times, like financial trading and network control. It is also the first demonstration of a quantitative quantum time advantage in relativistic cryptography, showing the enhanced cryptographic power of simultaneously considering quantum and relativistic physics.

Recent advances in loophole-free Bell tests have profoundly impacted quantum cryptography, yet their security assumes trusted random number generators (RNGs) for measurement choices—a vulnerability termed the freedom-of-choice loophole. Here, we demonstrate that classical systems can spoof Bell violations under ostensibly loophole-free conditions using compromised RNGs. By synchronizing laser-generated separable states with imperfect RNG outputs in an optical setup, we simulate a CHSH test closing locality and detection loopholes. With full RNG access, we achieve a near-maximal CHSH value of 3.99, exceeding quantum limits. Crucially, partial RNG knowledge suffices: predetermining 10.6% of bits reproduces our “loophole free” optical system's CHSH value of 2.007, while Santha-Vazirani generators with 0.38-biased bits enable optimal spoofing. Even weakly correlated RNGs coordinated via entangled states—deviating by 0.04 from independence—allow violations. Prediction-based ratio analysis gives a P-value upper bound of 10^(-18266), misleadingly implying non-classicality if RNG flaws are ignored. Strikingly, we extract "device-independent" random bits from simulated outcomes, mirroring cryptographic protocols. This exposes a critical flaw: compromised input randomness invalidates security guarantees in Bell-inequality-based cryptography. Our findings mandate rigorous verification of both RNG integrity and Bell violations to ensure quantum cryptographic security.

Quantum key distribution (QKD) holds the potential to establish secure keys over long distances. The distance of point-to-point QKD secure key distribution is primarily impeded by the transmission loss inherent to the channel. In the quest to realize a large-scale quantum network, increasing the QKD distance under current technology is of great research interest. Here we adopt the 3-intensity sending-or-not-sending twin-field QKD (TF-QKD) protocol with the actively-odd-parity-pairing method. The experiment demonstrates the feasibility of secure QKD over a 1002 km fibre channel considering the finite size effect. The secure key rate is $3.11 10^{-12}$ per pulse at this distance. Furthermore, by optimizing parameters for shorter fiber distances, we conducted performance tests on key distribution for fiber lengths ranging from 202 km to 505 km. Notably, the secure key rate for the 202 km, the normal distance between major cities, reached 111.74 kbps.