Theory for low-dimensional quantum materials

·Surface & Interface Modeling

·Massive Manipulation & Artificial Creation

Recent publications

Recent News

研究组二维界面磁电调控合作研究获新进展

研究组二维界面磁电调控合作研究获新进展

Dec 24, 2024

王聪副研究员、季威教授等与北京大学等机构合作，通过第一性原理计算与高精密电容测量，观察到双层石墨烯与CrOCl异质结中的磁电协同控制行为。相关成果于2024年12月发表在Advanced Materials上。

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研究组铁电畴壁原子尺度演化机制合作研究获新突破

研究组铁电畴壁原子尺度演化机制合作研究获新突破

Dec 12, 2024

物理学院季威教授研究团队与复旦大学和浙江大学的研究者联合研究了二维范德华铁电半导体α-In₂Se₃的层间堆叠方式对铁电畴壁形态、翻转行为及相变路径的影响。澄清了界面堆叠与铁电畴壁运动方式之间的内在联系。研究成果于2024年12月发表在Nature Communications上。

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See small, think big

Believe in seeing

  • Microscopes empower human beings the capability of seeing nanostructures. We are interested in modeling those nanostructures being seen using a STM, nc-AFM or STEM. Interplay of those nanostructure with probes, e.g. a STM tip or electron beams, is of paramount importance, modeling of which is one of our missions.
  • We, working closely with our experimental collaborators, observed the world’s first images of hydrogen bonding (Science 2013) and N…N quasi-bonding (Nat. Nanotech. 2018). The latter also verifies that the hydrogen bonding was indeed detected in the Science work.

At van der Waals gaps

  • It was believed that van der Waals (vdW) interactions do not appreciably modify electronic structures of materials. However, we recently found significant wave function overlaps at inter-block regions (known as vdW gaps) of low-dimensional materials, called covalent-like quasi-bonding, which helps predict or explain many layer-dependent bandgaps,  magnetism and electrical polarizations .
  • We recently uncovered a few  magnetic coupling mechanisms across their vdW gaps in e.g. CrI3 (PRB 2019), CrSe2 (PRB 2020 & Nat. Mater. 2021), CrTe2 (PRB 2020 & Nat. Communi. 2022), NiI2 and CrSBr, and found an OOP ferroelectricity in a MoS2/WS2 bilayer (Science 2022).

Atomic Electronics

  • Moore’s law is a visionary guideline that keeps transistors evolving in the past over 60 years. As the channel length approaches the atomic scale, now it is 12 nm (tens of atoms) in IBM or Samsung’s 2 or 3 nm CMOS techniques,  many of us believe that the atomicscale is the smallest sizescale that our devices, with novel functionalities, can work properly.
  • We are dedicated to explore and propose novel functionalities  of atomic devices, with moving the position or changing the state of an individual atom (small cluster).
  • We  proposed the world’s smallest electret and demonstrated its device functionality in a Gd@C82 devices (Nat. Nanotech. 2020). 

The Group

Group Leader

Ji, Wei

Dr. Ji, Wei
Professor of Physics
Rm. 205A, Physics Bldg. Zhongguancun North Campus, RUC

wji@ruc.edu.cn
+86-10-62515597

senier researcher

Wang, Cong

Dr. Wang, Cong
Research Assoc. Prof.
Rm. 209, Physics Bldg.
Zhongguancun North Campus, RUC

wc_phys@ruc.edu.cn
+86-10-62517997

Adjacent Member

Qiao, Jingsi

Dr. Qiao, Jingsi
Tenure-tracked Assoc. Prof.
Rm. 206, Physics Bldg.
Zhongguancun North Campus, RUC

qiaojs@ruc.edu.cn
+86-10-62517997

Post-doctoral fellow

Liu, Nanshu

Dr. Liu, Nanshu
Postdoctoral Fellow
Rm. 209, Physics Bldg. Zhongguancun North Campus, RUC

liuns@ruc.edu.cn
+86-10-62517997

PhD student

Wu, Linlu

Ms. Wu, Linlu
PhD student (P4) 
Rm. 206, Physics Bldg.
Zhongguancun North Campus, RUC

wulinlu@ruc.edu.cn
+86-10-62517997

PhD Student

Wang, Lvjing

Mr. Wang, Lvjing
PhD student (P4) 
Rm. 206, Physics Bldg.
Zhongguancun North Campus, RUC

lvjinwang@ruc.edu.cn
+86-10-62517997

Join the group. Invent the world’s smallest device

see group gallery