Observation of phonon Stark effect

Zhiheng Huang; Yunfei Bai; Yanchong Zhao; Le Liu; Xuan Zhao; Jiangbin Wu; Kenji Watanabe; Takashi Taniguchi; Wei Yang; Dongxia Shi; Yang Xu; Tiantian Zhang; Qingming Zhang; Ping-Heng Tan; Zhipei Sun; Sheng Meng; Yaxian Wang; Luojun Du; Guangyu Zhang

doi:10.1038/s41467-024-48992-w

Observation of phonon Stark effect

Nat Commun. 2024 May 29;15(1):4586. doi: 10.1038/s41467-024-48992-w.

Authors

Zhiheng Huang^#^{1

2}, Yunfei Bai^#^{1

2}, Yanchong Zhao^{1

2}, Le Liu^{1

2}, Xuan Zhao^{1

2}, Jiangbin Wu³, Kenji Watanabe⁴, Takashi Taniguchi⁵, Wei Yang^{1

2}, Dongxia Shi^{1

2}, Yang Xu^{1

2}, Tiantian Zhang⁶, Qingming Zhang^{1

2

7}, Ping-Heng Tan³, Zhipei Sun⁸, Sheng Meng^{1

2

9}, Yaxian Wang¹⁰, Luojun Du^{11

12}, Guangyu Zhang^{13

14

15}

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
³ State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
⁴ Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan.
⁵ International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan.
⁶ CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190, China.
⁷ School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China.
⁸ QTF Centre of Excellence, Department of Electronics and Nanoengineering, Aalto University, Tietotie 3, FI-02150, Espoo, Finland.
⁹ Songshan Lake Materials Laboratory, Dongguan, Guangdong Province, 523808, China.
¹⁰ Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
¹¹ Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
¹² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
¹³ Beijing National Laboratory for Condensed Matter Physics; Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
¹⁴ School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
¹⁵ Songshan Lake Materials Laboratory, Dongguan, Guangdong Province, 523808, China. [email protected].

^# Contributed equally.

Abstract

Stark effect, the electric-field analogue of magnetic Zeeman effect, is one of the celebrated phenomena in modern physics and appealing for emergent applications in electronics, optoelectronics, as well as quantum technologies. While in condensed matter it has prospered only for excitons, whether other collective excitations can display Stark effect remains elusive. Here, we report the observation of phonon Stark effect in a two-dimensional quantum system of bilayer 2H-MoS₂. The longitudinal acoustic phonon red-shifts linearly with applied electric fields and can be tuned over ~1 THz, evidencing giant Stark effect of phonons. Together with many-body ab initio calculations, we uncover that the observed phonon Stark effect originates fundamentally from the strong coupling between phonons and interlayer excitons (IXs). In addition, IX-mediated electro-phonon intensity modulation up to ~1200% is discovered for infrared-active phonon A_2u. Our results unveil the exotic phonon Stark effect and effective phonon engineering by IX-mediated mechanism, promising for a plethora of exciting many-body physics and potential technological innovations.