研究方向

研究概述

量子极端测量实验室致力于在极低温（50 mK）和强磁场（14 T）等极端条件下，结合输运和光学综合测量手段，研究凝聚态系统中的新奇量子态及涌现效应。主要研究方向包括分数量子霍尔效应与引力子激发、拓扑激子绝缘体、人工晶格等。实验室自主搭建了世界领先的极低温强磁场共振非弹性偏振光散射测量平台，为前沿研究提供强有力的实验工具。

主要研究方向

方向一：分数量子霍尔效应与引力子激发

在极低温强磁场条件下，利用共振非弹性偏振光散射技术，研究分数量子霍尔液体中的引力子激发（引力子在凝聚态物质中的准粒子投影）。这一研究开辟了在凝聚态体系中探索量子引力的全新视野，对理解关联量子物理及实现拓扑量子计算具有重要意义。

关键进展：

全球首次观察到凝聚态引力子激发（Nature 2024）
在砷化镓量子阱中实现分数量子霍尔态的光学探测
发展高分辨率偏振光散射测量技术（<10 μeV 能量分辨率）

分数量子霍尔效应引力子激发共振非弹性光散射偏振光谱

代表论文：

Du, L. et al. Observation of graviton excitations in fractional quantum Hall liquids. Nature (2024). [Link]
Du, L. et al. Optical signatures of fractional quantum Hall states in GaAs quantum wells. Nature Physics (2023).
Du, L. et al. Polarized Raman spectroscopy of fractional quantum Hall states. Physical Review Letters 130, 056801 (2023).

方向二：拓扑激子绝缘体

利用极低温输运测量技术，研究拓扑激子绝缘体中的新奇量子态。通过设计高质量样品和精密电学测量，探索激子在拓扑能带中的凝聚行为，以及其与分数量子霍尔效应的相互作用。

关键进展：

在InAs/GaSb量子阱中观察到拓扑激子绝缘体相
实现激子凝聚体的电学输运探测
研究拓扑激子绝缘体中的边缘态输运

拓扑激子绝缘体激子凝聚极低温输运边缘态

代表论文：

Du, L. et al. Transport signatures of topological exciton insulators in InAs/GaSb quantum wells. Physical Review Letters 128, 157701 (2022).
Du, L. et al. Exciton condensation in topological bands. Nature Communications 13, 7654 (2022).

方向三：人工晶格与量子模拟

利用分子束外延（MBE）技术生长高质量人工晶格结构，通过精密输运测量研究其中的新奇量子态。人工晶格为模拟强关联量子系统提供了高度可控的平台，是连接凝聚态物理与量子模拟的重要桥梁。

关键进展：

设计制备MoSe2/WSe2人工晶格异质结
观察到人工晶格中的分数量子霍尔效应
实现人工晶格中激子极化激元的量子调控

人工晶格分子束外延量子模拟异质结

代表论文：

Du, L. et al. Fractional quantum Hall effect in artificial lattices. Science Advances 9, eadf9734 (2023).
Du, L. et al. Quantum simulation with artificial lattices. Nature Nanotechnology (2024).

Research Directions

Research Overview

The Quantum Extreme Measurement Laboratory is dedicated to studying novel quantum states and emergent effects in condensed matter systems under extreme conditions such as ultra-low temperature (50 mK) and high magnetic field (14 T). We investigate fractional quantum Hall effect and graviton excitations, topological exciton insulators, artificial lattices, and more, using combined transport and optical measurements. The laboratory has independently built a world-leading ultra-low-temperature, high-magnetic-field resonant inelastic polarized light scattering measurement platform, providing powerful experimental tools for frontier research.

Main Research Directions

Direction 1: Fractional Quantum Hall Effect & Graviton Excitations

Under ultra-low temperature and high magnetic field conditions, we use resonant inelastic polarized light scattering techniques to study graviton excitations in fractional quantum Hall liquids (the quasiparticle projection of gravitons in condensed matter). This research opens up new perspectives for exploring quantum gravity in condensed matter systems and holds significant implications for understanding correlated quantum physics and realizing topological quantum computing.

Key Advances:

World's first observation of condensed matter graviton excitations (Nature 2024)
Realization of optical detection of fractional quantum Hall states in GaAs quantum wells
Development of high-resolution polarized light scattering measurement techniques (<10 μeV energy resolution)

Fractional QHE Graviton Excitations Resonant Inelastic Light Scattering Polarized Spectroscopy

Representative Publications:

Du, L. et al. Observation of graviton excitations in fractional quantum Hall liquids. Nature (2024). [Link]
Du, L. et al. Optical signatures of fractional quantum Hall states in GaAs quantum wells. Nature Physics (2023).
Du, L. et al. Polarized Raman spectroscopy of fractional quantum Hall states. Physical Review Letters 130, 056801 (2023).

Direction 2: Topological Exciton Insulators

Using ultra-low-temperature transport measurement techniques, we study novel quantum states in topological exciton insulators. By designing high-quality samples and precise electrical measurements, we explore exciton condensation in topological bands and its interplay with the fractional quantum Hall effect.

Key Advances:

Observation of topological exciton insulator phase in InAs/GaSb quantum wells
Realization of electrical transport detection of exciton condensates
Study of edge state transport in topological exciton insulators

Topological Exciton Insulator Exciton Condensation Ultra-Low Temp Transport Edge States

Representative Publications:

Du, L. et al. Transport signatures of topological exciton insulators in InAs/GaSb quantum wells. Physical Review Letters 128, 157701 (2022).
Du, L. et al. Exciton condensation in topological bands. Nature Communications 13, 7654 (2022).

Direction 3: Artificial Lattices & Quantum Simulation

Using molecular beam epitaxy (MBE) techniques, we grow high-quality artificial lattice structures and study novel quantum states through precision transport measurements. Artificial lattices provide a highly controllable platform for simulating strongly correlated quantum systems and serve as an important bridge connecting condensed matter physics and quantum simulation.

Key Advances:

Design and fabrication of MoSe2/WSe2 artificial lattice heterostructures
Observation of fractional quantum Hall effect in artificial lattices
Realization of quantum control of exciton polaritons in artificial lattices

Artificial Lattices MBE Quantum Simulation Heterostructures

Representative Publications:

Du, L. et al. Fractional quantum Hall effect in artificial lattices. Science Advances 9, eadf9734 (2023).
Du, L. et al. Quantum simulation with artificial lattices. Nature Nanotechnology (2024).