Shanghai Applications Lab Collaboration with Dr. Chen Guorui

Oxford Instruments Shanghai Applications Laboratory user Dr. Chen Guorui, associate professor at Shanghai Jiao Tong University, has published a paper ‘Tunable correlated Chern insulator and ferromagnetism in a moiré superlattice’ in Nature as the first author. This work was led by Prof. Wang Feng at UC Berkeley and in collaboration with Prof. Zhang Yuanbo from Fudan University and Prof. David Goldhaber-Gordon from Stanford University.

They discovered the coexistence of superconducting states, insulating states and ferromagnetic states in one trilayer graphene sample. For the first time, they turned graphene into a high-order Chern insulator, which is a consequence of the strong electron-electron interactions.

“Our discovery demonstrates that graphene is an ideal platform for studying different physics, ranging from single-particle physics, to superconductivity, and now topological physics to study quantum phases of matter in 2D materials,” Dr. Chen said. “It’s exciting that we can now explore new physics in a tiny device just 1 millionth of a millimetre thick.”

Dr. Chen (middle) with Oxford Instruments NanoScience team in Shanghai Applications Lab.

Dr. Chen’s history with Oxford Instruments

Dr. Chen was an experienced Oxford Instruments user when, while in China for the spring festival in February 2019, he thought to measure the quantum anomalous Hall effect (QAHE) in his trilayer graphene sample. He then contacted the Oxford Instruments NanoScience Shanghai Applications Lab and proposed to use our TeslatronPT for initial research. He was a guest in our lab for about two weeks and got exciting clues of the possible QAHE. The data bellow was collected in our 8T TeslatronPT at 1.5K and shows half quantized resistance of h/2e² at 2T.

Data collected in Shanghai Applications Lab

Seeing this, Dr. Chen realised a more prominent signal could be observed at an even lower temperature, which is when he travelled to Stanford, United States and measured fully developed half quantised state with Chern number equaling 2.

We’re very happy to see that in the paper, published in Nature, Dr. Chen acknowledged our Shanghai Applications Lab and we look forward to more collaborations with customers in our applications laboratories and wish the best for their success.