时间：2021年12月7日（周二） 16:00-17:30

Time: 16:00-17:30, Tuesday, December 7th, 2021

主持人: 西湖大学理学院讲席教授 Alexey Kavokin 博士

Host: Prof. Alexey Kavokin, Chair Professor of School of Science, Westlake University

地点：西湖大学云栖校区4号楼311会议室

Venue: Room 311, Building 4, Yunqi Campus

线上：Zoom会议 ID：825 0687 0859

Online：Zoom Meeting ID: 825 0687 0859

主讲嘉宾/Speaker：

Prof. Daniele Sanvitto

Research Director at the Institute of Nanotechnology

Italian National Research Council (CNR) 

主讲人简介/Biography:

Daniele Sanvitto is research director at the Institute of Nanotechnology of the Italian National Research Council (CNR) leading the group of Advanced Photonics. Before moving to the CNR he received his PhD at the University of Cambridge (UK) and took up different prestigious fellowships (Marie Curie, Ramon y Cajal, etc.) in several European institutions, including the Institut Jacques Monod in Paris, the University of Sheffield in UK and Universidad Autonoma de Madrid, in Spain.He is recipient of two ERC research grants on fundamental aspects of quantum fluids of lights and their applications in electro-optical devices. 

His research interests concern the strong light matter coupling in semiconductor and nanostructures. In particular his recent activities include the study of quantum fluids of exciton-polaritons on inorganic semiconductors as well as different organic and hybrid 2D material systems. Applications can span from ultrafast low-power optical components and electro-optical devices to quantum computation and neuromorphic computing. 

讲座摘要/Abstract:

There is a growing interest in the study of polaritonic systems, mixed states of photons and excitons, for both, the observation of quantum macroscopic phenomena, and the realisation of all-optical devices that could offer limitless advantages in terms of energy consumption, dissipation-less operation, and high clock frequencies [1]. Recently it has been demonstrated that such nonlinear fluids perform very well in neuromorphic computation and could even be used for hardware implementation of artificial neural networks [2, 3].

In this colloquium we will see several macroscopic quantum phenomena that can be observed in polariton condensates, both at low temperature in inorganic semiconductor microcavities, and at room temperature in organic based polaritons. In particular we will discuss the emergence of superfluidity in driven dissipative condensates, showing different manifestations of such a peculiar state [4-7].

We will also address the possibility of observing unique topological behaviours by exploiting both, the bare peculiar band structure of exciton-polaritons in a microcavity, as well as the more complex dispersions obtained by patterning a simple polariton waveguide. We will see, under certain conditions, the appearance of a Berry curvature [8, 9] that leads to an anomalous Hall drift as well as the emergence of artificial gauge fields acting on the propagation property of polariton fluids [10].

Example of a polariton quantum fluid, against an obstacle, above the sound velocity

References

[1] Sanvitto, D. & Kena-Cohen, S. The road towards polaritonic devices. Nat. Mater. 15, 1061–1073 (2016).

[2] D. Ballarini, et al. Polaritonic Neuromorphic Computing Outperforms Linear Classifiers. Nano Lett. 20, 3506 (2020).

[3] M Matuszewski, Energy-Efficient Neural Network Inference with Microcavity Exciton Polaritons, Phy. Rev. App. 16, 024045 (2021)

[4] D. Caputo, et al. Topological order and thermal equilibrium in polariton condensates. Nat. Mater. 17, 145–151 (2018).

[5] D. Caputo, et al. Josephson vortices induced by phase twisting a polariton superfluid, Nat. Phot. 13, 488 (2019)

[6] G. Lerario, et al. Room-temperature superfluidity in a polariton condensate. Nat. Phys. 13, 837 (2017).

[7] R. Panico, et al., Dynamics of a Vortex Lattice in an Expanding Polariton Quantum Fluid, Phys. Rev. Lett. 127, 047401 (2021)

[8] A. Gianfrate, et al., Measurement of the quantum geometric tensor and of the anomalous Hall drift. Nature 578, 381 (2020).

[9] L. Polimeno, et al. Tuning the Berry curvature in 2D Perovskite polaritons. Nat. Nanotech., doi: 10.1038/s41565-021-00977-2.

[10] A. Fieramosca, et al. Experimental investigation of a non-Abelian gauge field in 2D perovskite photonic platform, Optica 8, 1442 (2021).

讲座联系人/Contact:

理学院 陈老师 chenkeyu@westlake.edu.cn