Research Progress

Experimental Demonstration of High-Rate Measurement-Device-Independent Quantum Key Distribution over Asymmetric Channels

Measurement-device-independent quantum key distribution (MDI-QKD) can eliminate all detector side
channels and it is practical with current technology. Previous implementations of MDI-QKD all used two
symmetric channels with similar losses. However, the secret key rate is severely limited when different
channels have different losses. Here we report the results of the first high-rate MDI-QKD experiment over
asymmetric channels. By using the recent 7-intensity optimization approach, we demonstrate > 10 ×

Degenerate Bose gases near a d-wave shape resonance

Understanding quantum many-body systems with strong interactions and unconventional phases therein is one of the most challenging tasks in physics. In cold atom physics, this has been a focused research topic for nearly two decades, where strong interactions are naturally created and well manipulated by bringing the system close to a scattering resonance. However, most of the studies thus far have been limited to the s-wave resonance.

18 Qubits: USTC Scientists Set New Quantum Entanglement Record

The new world record of 18-qubit quantum entanglement with six photons’ three degrees of freedom (6 × 3 = 18) has been achieved by USTC physicists PAN Jianwei (project leader), LU Chaoyang, LIU Naile, WANG Xilin et al., surpassing the previous world record of 10-qubit entanglement they made in 2016. The successful control over the high-dimensional entanglement is the key for speeding up quantum computing and the future quantum network. This breakthrough was published as the Editors’ Suggestion in the journal Physical Review Letters within only three weeks of submission.

USTC Conducts the First Experiment on Boson Sampling with Photon Loss

Professor PAN Jianwei and Professor LU Chaoyang of the University of Science and Technology of China (USTC) carry out an experiment on boson sampling with photon loss in collaboration with Researcher YOU Lixing’s group of Shanghai Institute of Microsystem and Information Technology (SIMIT) of Chinese Academy of Sciences (CAS). The results show that boson sampling with a few photons lost can increase the sampling rate, which brings a demonstration of quantum supremacy closer to reality. This research is published in Physical Review Letters on June 6th as one of Editor’s Suggestions. The American Physical Society website Physics comments on the paper with a Viewpoint article entitled “Lost Photons Won’t Derail Quantum Sampling”.

[Xinhua] Chinese scientists conduct ground-to-space quantum teleportation

"Beam me up, Scotty." The famous "Star Trek" catchphrase has launched teleporting daydreams the world over.

Now Chinese scientists have completed an experiment straight out of the realms of science fiction - quantum teleportation - from the ground to the world's first quantum satellite.

The experiment was similar in some ways to the Star Trek mode of transport, except that the scientists beamed up the quantum states of photons rather than people.

[PhysicsWorld] Particle-free quantum communication is achieved in the lab

Four years ago, theoretical physicists proposed a new quantum-communication scheme with a striking feature: it did not require the transmission of any physical particles. The research raised eyebrows, but now a team of physicists in China claims it has demonstrated that the "counterfactual" scheme works. The group built an optical apparatus that it says can transfer a simple image while sending (almost) no photons in the process.

[Physics] Synopsis: Ten Photons in a Tangle

An entangled polarization state of ten photons sets a new record for multiphoton entanglement. Quantum computing requires multiple qubits entangled together. So far, only a handful of qubits have been coupled together successfully. A new experiment raises the bar with the entangling of ten photons, two more than the previous photon record. While still a ways off from what’s needed to make quantum computers competitive with classical ones, the entanglement of this many photons might be sufficient for certain quantum error correction codes and teleportation experiments.