Article
Physics, Multidisciplinary
Zherui Han, Xiaolong Yang, Sean E. Sullivan, Tianli Feng, Li Shi, Wu Li, Xiulin Ruan
Summary: This study considers multiple factors such as phonon anharmonicity, phonon renormalization, and electron-phonon coupling on the Raman peak frequency shift and linewidth in graphene samples. The results show that four-phonon scattering contributes significantly to the linewidth, increasing with temperature, while the temperature dependence of electron-phonon interactions reverses above a certain doping threshold.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Marten Duvel, Marco Merboldt, Jan Philipp Bange, Hannah Strauch, Michael Stellbrink, Klaus Pierz, Hans Werner Schumacher, Davood Momeni, Daniel Steil, G. S. Matthijs Jansen, Sabine Steil, Dino Novko, Stefan Mathias, Marcel Reutzel
Summary: This study investigates far-from-equilibrium many-body interactions using photoelectron spectroscopy and finds remarkable transient renormalizations of the quasiparticle self-energy due to non-equilibrium conditions. These observations can be explained by ultrafast scatterings between nonequilibrium electrons and strongly coupled optical phonons.
Article
Chemistry, Physical
Chenjing Quan, Xiao Xing, Tingyuan Jia, Zeyu Zhang, Chunwei Wang, Sihao Huang, Zhengzheng Liu, Juan Du, Yuxin Leng
Summary: The charge transfer process in two-dimensional graphene/transition metal dichalcogenides heterostructures was investigated. The study revealed the correlation between the hot phonon bottleneck effect in graphene and the charge transfer process. The existence of interlayer charge transfer in the heterostructure and its dependence on pump fluence were confirmed.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Chenjing Quan, Xiao Xing, Tingyuan Jia, Zeyu Zhang, Chunwei Wang, Sihao Huang, Zhengzheng Liu, Juan Du, Yuxin Leng
Summary: In this study, the hot carrier transport in graphene/transition metal dichalcogenides heterostructures was investigated using optical pump and terahertz probe spectroscopy. The results revealed the relationship between charge transfer and pump fluence, providing insights into the mechanism for further exploration of optoelectronic devices.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Xiaolong Yang, Zhe Liu, Fanchen Meng, Wu Li
Summary: Recent studies have shown the significance of electron-phonon interaction (EPI) in phonon transport at intermediate temperatures, where EPI can dominate over anharmonic phonon-phonon scattering in some metals, leading to an anomalous phonon transport regime. Using first-principles calculations, it was predicted that in bilayer graphene, tuning the doping level can drive phonon transport into the anomalous regime, resulting in a fivefold reduction of lattice thermal conductivity at room temperature. The origin of this anomalous behavior lies in mirror symmetry breaking, dominance of normal processes in anharmonic ph-ph scattering, and the indirect effect of EPI on K-L.
Article
Materials Science, Multidisciplinary
Jun Qian, Yilong Luan, Minsung Kim, Kai-Ming Ho, Yi Shi, Cai-Zhuang Wang, Yun Li, Zhe Fei
Summary: The electron-phonon interactions in few-layer graphene were studied using a femtosecond infrared laser-excited s-SNOM, revealing a strong coupling between IR phonons and ultra-hot electrons. The intensity of phonon resonance was found to be tunable by varying laser power, controlling electron temperature. High spatial resolution of s-SNOM enabled mapping of local phonon characteristics at sharp boundaries and nanostructures.
Article
Optics
Li Wang, Jinlai Liu, Bin Ren, Jie Song, Yongyuan Jiang
Summary: A heterostructured graphene/hBN/graphene nanodisk array was used to create an electrically tunable absorber within and outside the Reststrahlen band of hBN, achieving tuning of resonance absorption through phonon-plasmon-polariton hybridization. The hybrid phonon mode enabled significant shifts in resonant wavelength and sensitivity to electrical control.
Article
Chemistry, Multidisciplinary
Jiasheng Zhou, Haipeng Li, Ho-Kin Tang, Lei Shao, Kui Han, Xiaopeng Shen
Summary: In this paper, molecular dynamics simulations were used to investigate the phonon thermal transport in silicene/graphene heterostructures. The results showed that graphene dominates the thermal transport in the heterostructures, and heterostructuring can reduce the thermal conductivity of the graphene layer while increasing the thermal conductivity of the silicene layer. The interlayer interaction strength also affects the thermal conductivity and interfacial thermal resistance in the heterostructures.
Article
Physics, Applied
K. Park, J. Kim, S. Choi, S. Fan, C. Kim, D. G. Oh, N. Lee, S. -W Cheong, V. Kiryukhin, Y. J. Choi, D. Vanderbilt, J. H. Lee, J. L. Musfeldt
Summary: To explore the effects of spin-orbit coupling on spin-phonon interactions, we studied the infrared vibrational properties of chemically similar mixed metal oxides. Our findings showed significant shifts in the Co2+ shearing mode near 150 cm(-1) across the magnetic ordering temperature. These shifts were especially large in relative terms. The spin-phonon coupling constants were derived from interlayer exchange interactions and contained competing antiferromagnetic and ferromagnetic contributions.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Stavros Katsiaounis, Nikos Delikoukos, Antonios Michail, John Parthenios, Konstantinos Papagelis
Summary: We studied the effects of electron-phonon and phonon-phonon interactions on the linewidth of the G phonon in both unintentionally and intentionally doped polycrystalline chemical vapor deposited (CVD) graphene samples using conventional and time-resolved Raman spectroscopy. We found that the lifetime of the G phonon decreased approximately by 14% with increasing doping, contrary to the anticipated reduction in G phonon linewidth due to a decrement in electron-phonon contribution from first principles calculations. The CVD samples exhibited a decrease of approximately 30% in the electron-phonon coupling constant compared to exfoliated graphene samples. Additionally, the contribution of phonon-defect scattering to the G band linewidth was significant in CVD graphene samples due to their lower crystal quality compared to exfoliated graphene.
Article
Chemistry, Physical
Jiwon Jeon, Youngjae Kim, J. D. Lee
Summary: Pseudospin, a fundamental quantum number in graphene, can be changed by the rotation of phonons. By observing the phonon satellite accompanying the linearly pumped electron to the upper Dirac cone, we found that pseudospin exhibits rotation, nonzero angular momentum, and Berry curvature. We also identified the phonon responsible for pseudospin rotation as an elliptically polarized phonon, which can induce chiral phonon excitation without circularly polarized pumping.
Article
Chemistry, Multidisciplinary
Brigitte A. G. Lamers, Martin H. C. van Son, Freek de Graaf, Bart W. L. van den Bersselaar, Bas F. M. de Waal, Kazuki Komatsu, Hiroshi Sato, Takuzo Aida, Jose Augusto Berrocal, Anja R. A. Palmans, Ghislaine Vantomme, Stefan C. J. Meskers, E. W. Meijer
Summary: The assembly of highly ordered nanomaterials through charge transfer interactions is achieved in this study, where pyrene and naphthalenediimide functionalized oligodimethylsiloxanes are synthesized and co-assembled in bulk. By tuning the donor-acceptor interactions through connecting pyrene and NDI to the same oligomer or to two separate oligomers, different types of donor-acceptor molecules are obtained. The discreet length of the oligodimethylsiloxane units plays a crucial role in the formation of liquid crystalline materials and CT dimers.
MATERIALS HORIZONS
(2022)
Article
Nanoscience & Nanotechnology
Gonzalo Alvarez-Perez, Arturo Gonzalez-Moran, Nathaniel Capote-Robayna, Kirill V. Voronin, Jiahua Duan, Valentyn S. Volkov, Pablo Alonso-Gonzalez, Alexey Y. Nikitin
Summary: This study reports on a new technology that actively tunes anisotropic Phonon polaritons (PhPs) supported by biaxial vdW slabs by simply gating an integrated graphene layer. Excitingly, the study demonstrates active tuning of optical topological transitions, enabling control of PhPs canalization along different directions.
Article
Chemistry, Physical
Nimrod Benshalom, Maor Asher, Remy Jouclas, Roman Korobko, Guillaume Schweicher, Jie Liu, Yves Geerts, Olle Hellman, Omer Yaffe
Summary: We have discovered that the polarization dependence of Raman scattering in organic crystals at finite temperatures can only be explained using a fourth-rank tensor formalism. This extension of the second-rank Raman tensor is a result of the off diagonal components in the crystal self-energy affecting the light scattering mechanism. Therefore, we have established a new manifestation of phonon-phonon interaction in inelastic light scattering, which is distinct from the well-known phonon lifetime.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Zhongyao Li, Jianyuan Xue
Summary: The magnetic anisotropy of CoN4-graphene and CoN3-graphene has been systematically studied in this study. It was found that CoN4-graphene has an in-plane easy magnetization direction, while CoN3-graphene has an out-of-plane easy magnetization direction. The magnetic anisotropy energy can be tuned by injecting charge or applying strain. Particularly, for CoN3-graphene, both charge injection and tensile strain can change the easy magnetization direction from out-of-plane to in-plane. The tunable magnetic anisotropy may promote the application of Co-N-doped graphene in spintronic devices.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Xuanye Wang, Jason W. Christopher, Anna K. Swan
SCIENTIFIC REPORTS
(2017)
Article
Engineering, Electrical & Electronic
Jason W. Christopher, Mounika Vutukuru, David Lloyd, J. Scott Bunch, Bennett B. Goldberg, David J. Bishop, Anna K. Swan
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2019)
Article
Engineering, Electrical & Electronic
Mounika Vutukuru, Jason W. Christopher, Corey Pollock, David J. Bishop, Anna K. Swan
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2019)
Correction
Chemistry, Multidisciplinary
David Lloyd, Xinghui Liu, Jason W. Christopher, Lauren Cantley, Anubhav Wadehra, Brian L. Kim, Bennett B. Goldberg, Anna K. Swan, J. Scott Bunch
Article
Nanoscience & Nanotechnology
Yuyu Li, Pablo Ferreyra, Anna K. Swan, Roberto Paiella
Review
Nanoscience & Nanotechnology
Yuyu Li, Khwanchai Tantiwanichapan, Anna K. Swan, Roberto Paiella
Article
Nanoscience & Nanotechnology
Mounika Vutukuru, Hossein Ardekani, Zhuofa Chen, Ryan L. Wilmington, Kenan Gundogdu, Anna K. Swan
Summary: Nonuniform strain on multilayer transition-metal dichalcogenide nanosheets can dramatically enhance photoluminescence by causing charge and exciton funneling to strain apex, reducing exciton binding energy and renormalizing the band gap, leading to dissociation of bound excitons into free electron-hole pairs, demonstrating the potential for effective manipulation of light-matter interaction in these atomically thin materials for strain-engineered optoelectronics.
ACS APPLIED NANO MATERIALS
(2021)
Article
Instruments & Instrumentation
Hossein Ardekani, Ryan L. Wilmington, Mounika Vutukuru, Zhuofa Chen, Ryan Brandt, Anna K. Swan, Kenan Gundogdu
Summary: This study presents a method to significantly increase the sensitivity of lock-in detection by implementing tuned RC circuits and peak detector circuits for electric pulse shaping. Benchmark measurements on samples demonstrate the effectiveness of this method in improving lock-in detection signal enhancement.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Review
Materials Science, Multidisciplinary
Yuyu LI, Mathan Ramaswamy Krisshnamurthi, Weijun Luo, Anna K. Swan, Xi Ling, Roberto Paiella
Summary: Graphene metasurfaces with active tunability are a promising candidate for terahertz wavelength optics. This review summarizes recent research on the development of tunable graphene metasurfaces for wavefront shaping and light emission at terahertz frequencies. Different design strategies and solutions for constituent meta-units are presented. The development of these devices is discussed, including the challenges and proposed solutions. The resulting metasurface technology is expected to have a significant impact on a wide range of THz device applications.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Nanoscience & Nanotechnology
Zhuofa Chen, Weijun Luo, Liangbo Liang, Xi Ling, Anna K. Swan
Summary: Strain engineering allows for control over the band structure in transition-metal dichalcogenides, leading to various optoelectronic capabilities. By experimentally introducing strain, it has been observed that negative trions accumulate while positive trions almost disappear, indicating the potential to separate electrons and holes using strain.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Weijun Luo, Alexander Puretzky, Benjamin Lawrie, Qishuo Tan, Hongze Gao, Anna K. Swan, Liangbo Liang, Xi Ling
Summary: The effect of Coulomb interactions on the brightness, single photon purity, and operating temperatures of strain-localized GaSe single-photon emitters (SPEs) was investigated. Electrostatic doping was used to suppress nonradiative recombination, leading to improved emission intensity, single photon purity, and increased operating temperature.
Article
Nanoscience & Nanotechnology
Weijun Luo, Alexander A. A. Puretzky, Benjamin J. J. Lawrie, Qishuo Tan, Hongze Gao, Zhuofa Chen, Alexander V. V. Sergienko, Anna K. K. Swan, Liangbo Liang, Xi Ling
Summary: This study reports the deterministic spatial localization of strain-induced single-photon emitters (SPEs) in multilayer GaSe by nanopillar arrays. The strain-controlled quantum confinement effect introduces well-isolated sub-bandgap photoluminescence and suppresses the broad band edge photoluminescence. Clear photon-antibunching behavior is observed from the quantum dot-like GaSe sub-bandgap exciton emission at 3.5 K. The strain-dependent confinement potential and brightness are strongly correlated, suggesting a promising route for tuning and controlling SPEs. The comprehensive investigations of strain-engineered GaSe SPEs provide a solid foundation for the development of 2D devices for quantum photonic technologies.
Article
Chemistry, Analytical
Zhuofa Chen, Yousif Khaireddin, Anna K. Swan
Summary: The impact of the environment on the properties of graphene can be evaluated by Raman spectroscopy, and a deep learning model has been developed to classify graphene Raman spectra according to different charge densities and dielectric environments, overcoming variations and challenges in accurate spectral analysis.
Proceedings Paper
Engineering, Electrical & Electronic
Yuyu Li, Pablo Ferreyra, Anna K. Swan, Roberto Paiella
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
K. Tantiwanichapan, X. Wang, H. Durmaz, Y. Li, A. Swan, R. Paiella
2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2017)
