报告人：Mikhail Glazov (Ioffe Institute, St. Petersburg, Russia)

时 间：2026年4月16日（周四）下午15：00

地 点：良乡校区，物理实验中心229会议室

摘要：

In the past decade, atomically thin semiconductors based on transition metal dichalcogenides (TMDCs), such as MoS₂, MoSe₂, WS₂, WSe₂, and similar materials, have attracted particular attention from researchers due to their unusual physical properties. Prominent Coulomb effects manifested in large exciton binding energies (hundreds of meV), chiral selection rules for optical transitions, the coupling of spin and valley degrees of freedom of charge carriers (spin-valley locking), the ability to form van der Waals heterostructures with tunable properties based on TMD monolayers and boron nitride, moiré effects in such structures — this is far from a complete list of the distinctive features of these semiconductors [1,2].

The combination of strong excitonic effects and bright optical response of atomically thin TMDCs has opened up wide possibilities for studying not only classical topics in exciton spectroscopy — Rydberg series of exciton states, fine structure of excitons, their electro- and magneto-optics, optical harmonic generation on excitons — but has also made it possible to investigate the processes of exciton propagation in the plane of a two-dimensional crystal [3]. In addition to the expected diffusive propagation of excitons, mysterious effects were discovered in the very first experiments, such as the formation of exciton halos [4], which is associated with the specific nature of two-dimensional semiconductors, their band structure, and interparticle interaction effects.

In my talk, after a brief introduction to the physics of atomically thin semiconductors, an overview of exciton transport effects will be presented. Particular attention will be paid to comparing developed theoretical models with experimental data. The main phenomena described include:

— Nonlinear exciton diffusion and interaction effects [4];

— Phonon drag effects on electrons and the Seebeck effect [5,6];

— Manifestations of exciton interference — weak localization — in diffusion [7];

— Exciton diffusion in a Fermi sea of free charge carriers [8];

— Transport and "negative" diffusion in TMD heterobilayers [9];

— Ultrafast — quasi-hydrodynamic — exciton propagation [10-14].

Future research prospects and open problems will also be outlined.

[1] Gang Wang, et. al., Rev. Mod. Phys. 90, 021001 (2018).

[2] Yao Xiao, et al., Matter 3, 1142 (2020).

[3] A. Chernikov, M. Glazov, Exciton diffusion in 2D van der Waals semiconductors, in Semiconductors and Semimetals, Elsevier, Amsterdam (2023).

[4] Marvin Kulig, et al., Phys. Rev. Lett. 120, 207401 (2018).

[5] M. M. Glazov, Phys. Rev. B 100, 045426 (2019).

[6] R. Perea-Causín, et al., Nano Letters 19, 7317 (2019).

[7] K. Wagner, et al., Phys. Rev. Lett. 127, 076801 (2021).

[8] K. Wagner, Z. A. Iakovlev, et al., Nano Lett. 23, 4708 (2023).

[9] E. Wietek et al., Phys. Rev. Lett. 132, 016202 (2024).

[10] Andrés Granados del Águila, et al., Nature Nanotechnol. 18, 1012 (2023).

[11] M. M. Glazov, Nat. Nanotechnol. 18, 972 (2023).

[12] M.M. Glazov and R.A. Suris, JETP 166, 18 (2024).

[13] V. N. Mantsevich and M. M. Glazov, Phys. Rev. B 110, 165305 (2024).

[14] A. M. Shentsev, M. M. Glazov, Phys. Rev. B 111, 045301 (2025).

简历：

Prof. Mikhail Glazov, Corresponding Member of the Russian Academy of Sciences, is a distinguished condensed matter theorist working at the Ioffe Institute (Principal Scientific Researcher) and holding the Chair of Condensed Matter Physics at Academic University, St. Petersburg. His research focuses on two-dimensional materials, semiconductor spintronics, and the physics of excitons. He has made seminal contributions to the theory of excitons in transition‑metal dichalcogenides, nonlinear transport in graphene, electron and nuclear spin dynamics and fluctuations, and Rydberg excitons in semiconductors.

He defended both his PhD thesis (2008) and Habilitation thesis (Doctor of Sciences) (2012) at the Ioffe Institute. Prof. Glazov has been honored with the Medal and Prize for Young Researchers of the Russian Academy of Sciences (2014), the Euler Prize by the St. Petersburg Government and the RAS St. Petersburg Scientific Center (2015) and was elected Corresponding Member of the Russian Academy of Sciences in 2016. He serves on the editorial board of Physics of the Solid State, was an editorial board member of Physical Review B (until 2025) and was a member of the C8 Commission on Semiconductors of IUPAP (until 2025).

联系方式：gw@bit.edu.cn

邀请人： 王刚 教授

网 址：http://physics.bit.edu.cn/

承办单位：物理学院、先进光电量子结构设计与测量教育部重点实验室