Article
Chemistry, Multidisciplinary
Rongguang Du, Huatian Hu, Tong Fu, Zhifeng Shi, Shunping Zhang, Hongxing Xu
Summary: We have successfully extracted the individual decay channels of a coupled plasmon-exciton system using correlated single-particle absorption and scattering measurements. The plasmon channel exhibits clear Rabi splitting, while the exciton channel does not. The discrepancy in the absorption and scattering spectra is mainly attributed to the distinct contributions of the plasmon and exciton channels in the absorption and scattering process. These findings offer insights into plasmon-exciton interaction in an open cavity and have implications for the design of plexcitonic devices in ultrafast nonlinear nanophotonics.
Article
Chemistry, Multidisciplinary
Wei-Hsiang Lin, Pin Chieh Wu, Hamidreza Akbari, George R. Rossman, Nai-Chang Yeh, Harry A. Atwater
Summary: Efficient tailoring of valley-polarized photoluminescence from monolayer WS2 at room temperature through surface plasmon-exciton interactions with plasmonic Archimedes spiral (PAS) nanostructures is reported. The degree of valley polarization of WS2 at room temperature can be significantly enhanced using PAS, and further enhancement and control of excitonic valley polarization is demonstrated by electrostatically doping monolayer WS2.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Deepankur Thureja, Atac Imamoglu, Tomasz Smolenski, Ivan Amelio, Alexander Popert, Thibault Chervy, Xiaobo Lu, Song Liu, Katayun Barmak, Kenji Watanabe, Takashi Taniguchi, David J. Norris, Martin Kroner, Puneet A. Murthy
Summary: This study demonstrates electrically controlled quantum confinement of neutral excitons in 2D semiconductors, achieving confinement below 10 nm. The technique provides an experimental route towards creating scalable arrays of identical single-photon sources and has wide-ranging implications for realizing strongly correlated photonic phases and on-chip optical quantum information processors.
Article
Chemistry, Multidisciplinary
Jingang Li, Kan Yao, Yun Huang, Jie Fang, Pavana Siddhartha Kollipara, Donglei Emma Fan, Yuebing Zheng
Summary: In this work, chemically synthesized transition metal dichalcogenide (TMDC) nanowires are used as dielectric nanoresonators to support both excitonic and Mie resonances. Strong light-matter couplings and tunable exciton polaritons are demonstrated in individual nanowires. The TMDC nanoresonators, with highly tunable optical properties, have potential applications in tunable optical nanodevices.
ADVANCED MATERIALS
(2022)
Article
Physics, Applied
Chao Liu, Cuixiu Xiong, Min Li, Banxian Ruan, Baihui Zhang, Enduo Gao, Kuan Wu, Xia Chang, Wenke Xie, Hongjian Li
Summary: The study investigates the interaction between black phosphorus and metal-generated polaritons, revealing anti-crossing characteristics in the strong coupling region in the spectrum with angular resolution as a variable. The proposed structure can achieve a Rabi splitting of 65-150 meV, and increasing dielectric permittivity effectively enlarges the Rabi splitting, as demonstrated by the dispersion relation and coupled harmonic oscillator model. This research lays the foundation for the application of polarization devices and strong coupling platforms.
APPLIED PHYSICS EXPRESS
(2021)
Article
Nanoscience & Nanotechnology
Hongwu Tang, Fang Luo, Ziru Cui, Yang Xiao, Wei Xu, Zhihong Zhu, Shula Chen, Xiao Wang, Yanping Liu, Jinbin Wang, Gang Peng, Shiqiao Qin, Mengjian Zhu
Summary: Facile control of the wavelength of light emitters is crucial for optoelectronics and photonics applications. In this study, by utilizing the Joule heating effect, the refractive index of silicon-based waveguides can be modulated for reconfigurable nanophotonic circuits. The authors demonstrate electrically controlled wavelength-tunable photoluminescence from vertical van der Waals heterostructures combined by graphene and 2D-TMDCs. The electric control of the PL wavelength and the bandgap reduction of TMDCs are reversible and can be achieved by applying a moderate electric field to the graphene substrate.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Tongyao Zhang, Siwen Zhao, Anran Wang, Zhiren Xiong, Yingjia Liu, Ming Xi, Songlin Li, Hechang Lei, Zheng Vitto Han, Fengqiu Wang
Summary: By contacting a monolayer MoSe2 with a 2D ferromagnetic semiconductor, researchers have successfully manipulated the valley-polarization of MoSe2 and fabricated a spin functional device with both electrical and magnetic tunability. This study provides new insights into the manipulation of valley-polarization and represents an important step forward in the development of field-controlled 2D magneto-optoelectronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Ruhao Liu, Yaming Zhang, Yuankai Zhou, Jiaheng Nie, Lijie Li, Yan Zhang
Summary: This study investigates the properties of spin and valley transport in piezotronics valley transistors based on a normal/ferromagnetic/normal (NFN) structure of monolayer transition metal dichalcogenides (TMDs). The Rabi frequency can reach up to 4200 MHz using the piezotronics effect, which is about 1000 times higher than that of ZnO/CdO quantum well devices. The strain-induced strong polarization allows for control of the spin and valley transport properties in piezo-phototronic transistors. The theoretical calculations include the spin and valley conductance as well as the spin and valley polarizability. The strong polarization can be used to manipulate the valley qubit, thereby paving a new way for quantum computing applications based on piezotronic valley transistors.
Article
Chemistry, Multidisciplinary
Dongwon Shin, Hyeonbeom Kim, Sung Ju Hong, Sehwan Song, Yeongju Choi, Youngkuk Kim, Sungkyun Park, Dongseok Suh, Woo Seok Choi
Summary: Graphene and LaCoO3 hybrid heterostructure exhibits electrically tunable spin-exchange splitting, providing an opportunity for spin polarization control in spintronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Applied
Meng Qin, Yu Zhang, Hai-Xiao Xiao, Hong-Ju Li, Chun-Xiao Fan, Feng Wu
Summary: This study investigates dual-band perfect absorption and hybridization on multilayer WS2 gratings with metallic substrates using the finite-difference time-domain method and coupled-mode theory. The results show that achieving dual-band perfect absorption in a single-port system relies on two independent critical couplings.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Yiying Yan, Tadele T. Ergogo, Zhiguo Lu, Lipeng Chen, JunYan Luo, Yang Zhao
Summary: The study focuses on the vacuum Rabi splitting of a qubit ultrastrongly coupled to a cavity mode and a radiation reservoir, showing that the Lamb shift plays an essential role in modifying the coupling. As the cavity-qubit coupling increases, the emission spectrum undergoes changes with peaks narrowing and broadening until they have similar widths.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Multidisciplinary Sciences
SiJia Hui, Feng Wen, Minghui Zhang, ShaoWei Zhang, YuanJie Yang, ZhiPing Dai, YungPeng Su, YanPeng Zhang, HongXing Wang
Summary: The study revealed that dark state can modulate the number of VRS peaks and OB thresholds. Dark resonance can determine the asymmetric OB distribution of nested type and symmetric OB distribution of cascade type. The distinctive OB thresholds in two kinds of interaction were also studied.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Applied
Chun Li, Weili Li, Siyu Duan, Jingbo Wu, Benwen Chen, Shengxin Yang, Runfeng Su, Chengtao Jiang, Caihong Zhang, Biaobing Jin, Ling Jiang, Lin Kang, Weiwei Xu, Jian Chen, Peiheng Wu
Summary: An electrically tunable superconducting metamaterial was presented for modulating terahertz waves, achieving a relatively high modulation depth and group delay. Good agreement was observed between experimental and simulated transmission spectra, and the physical mechanism was well explained with a hybrid coupling model. The tuning of group delay of THz waves is of great significance for THz technology applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Min Zhang, Yuan Tian, Xingzhou Chen, Zheng Sun, Xiaolong Zhu, Jian Wu
Summary: This study reports the plasmon-exciton coupling in a hybrid system with a plasmonic metasurface. By finely tuning the geometric size of the plasmonic nanostructures, the dispersion relation of the coupled plasmon and exciton can be significantly modified. The experimental results show a strong coupling behavior with a achieved Rabi splitting up to 200 meV at room temperature, in ambient conditions. The effective tailoring of the plasmon-exciton coupling with the plasmonic metasurfaces provides a testing platform for studying quantum electromagnetics at the subwavelength scale and exploring plasmonic polariton Bose-Einstein condensation at room temperature.
Article
Chemistry, Multidisciplinary
He Liu, Ke Wang, Fei Gao, Jin Leng, Yang Liu, Yu-Chen Zhou, Gang Cao, Ting Wang, Jianjun Zhang, Peihao Huang, Hai-Ou Li, Guo-Ping Guo
Summary: Hole spin qubits based on germanium have strong tunable spin-orbit interaction and ultrafast qubit operation speed. We demonstrate that the Rabi frequency of a hole spin qubit in a Ge hut wire double quantum dot can be electrically tuned through the detuning energy and middle gate voltage. The discovery of an ultrafast and electrically tunable Rabi frequency in a hole spin qubit has potential applications in semiconductor quantum computing.
Article
Chemistry, Multidisciplinary
Dmitry Lebedev, Jonathan Tyler Gish, Ethan Skyler Garvey, Teodor Kosev Stanev, Junhwan Choi, Leonidas Georgopoulos, Thomas Wei Song, Hong Youl Park, Kenji Watanabe, Takashi Taniguchi, Nathaniel Patrick Stern, Vinod Kumar Sangwan, Mark Christopher Hersam
Summary: 2D magnetic materials have promising applications in quantum and spintronic devices. 2D antiferromagnetic materials are of interest due to their insensitivity to external magnetic fields and faster switching speeds compared to 2D ferromagnets. However, their lack of macroscopic magnetization hampers the detection and control of antiferromagnetic order, emphasizing the need for magneto-electrical measurements.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Dohun Kim, Byungmin Kang, Yong-Bin Choi, Kenji Watanabe, Takashi Taniguchi, Gil-Ho Lee, Gil Young Cho, Youngwook Kim
Summary: We introduce a novel two-dimensional electronic system called twisted bilayer graphene with a large twist angle, which exhibits ultrastrong interlayer interactions and is ideal for realizing interlayer-coherent excitonic condensates. By fully exploiting the sub-nanometer atomic separation and geometrically suppressed interlayer electron tunneling, we demonstrate the appearance of a sequence of odd-integer quantum Hall states with interlayer coherence at the second Landau level (N = 1). These states have energy gaps of order 1 K, several orders of magnitude greater than those in GaAs. Experimental observations of various quantum Hall phase transitions largely support our phenomenological model calculations. Therefore, we establish the excellent platform of a large twist angle system for high-temperature excitonic condensation.
Article
Nanoscience & Nanotechnology
Ryoichi Kato, Haruki Uchiyama, Tomonori Nishimura, Keiji Ueno, Takashi Taniguchi, Kenji Watanabe, Edward Chen, Kosuke Nagashio
Summary: In this study, high-performance p-type FETs were achieved by selectively applying surface charge-transfer doping from WOx to the access region of WS2 and WSe2. The p-type conversion of intrinsically n-type trilayer WSe2 FET was successfully achieved by reducing the Schottky barrier width and injecting holes into the valence band. However, trilayer WS2 did not show clear p-type conversion due to its lower valence band maximum compared to trilayer WSe2. Using h-BN as a TG insulator, a high-performance p-type WSe2 FET with negligible hysteresis was achieved.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Kento Sasaki, Yuki Nakamura, Hao Gu, Moeta Tsukamoto, Shu Nakaharai, Takuya Iwasaki, Kenji Watanabe, Takashi Taniguchi, Shinichi Ogawa, Yukinori Morita, Kensuke Kobayashi
Summary: Placing a sensor close to the target at the nano-level is a central challenge in quantum sensing. We demonstrate magnetic field imaging with a boron vacancy (V-B(-)) defects array in hexagonal boron nitride with a few 10 nm thickness. The sensor array allows us to visualize the magnetic field induced by the current in the straight micro wire with a high spatial resolution. Each sensor exhibits a practical sensitivity of 73.6 mu T/Hz(0.5), suitable for quantum materials research. Our technique of arranging V-B(-) quantum sensors periodically and tightly on measurement targets will maximize their potential.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Martin Endres, Artem Kononov, Hasitha Suriya Arachchige, Jiaqiang Yan, David Mandrus, Kenji Watanabe, Takashi Taniguchi, Christian Schoenenberger
Summary: In this study, we measured a 4N-periodic switching current through an asymmetric SQUID formed by the higher-order topological insulator WTe2. We found that a high asymmetry in critical current and negligible loop inductance alone were not sufficient to reliably measure the current-phase relation. Instead, we discovered that our measurement was heavily influenced by additional inductances originating from the self-formed PdTex inside the junction. We developed a method to numerically recover the current-phase relation and found that the 1.5 μm long junction was best described in the short ballistic limit. Our results highlight the complexity of subtle inductance effects that can lead to misleading topological signatures in transport measurements.
Article
Multidisciplinary Sciences
Wenjin Zhao, Bowen Shen, Zui Tao, Zhongdong Han, Kaifei Kang, Kenji Watanabe, Takashi Taniguchi, Kin Fai Mak, Jie Shan
Summary: Scientists have realized synthetic Kondo lattice in AB-stacked MoTe2/WSe2 moire bilayers, observing heavy fermions and demonstrating gate-tunable Kondo temperatures. This study opens the possibility of accessing the phase diagram of the Kondo lattice using semiconductor moire materials.
Article
Nanoscience & Nanotechnology
Kaifei Kang, Wenjin Zhao, Yihang Zeng, Kenji Watanabe, Takashi Taniguchi, Jie Shan, Kin Fai Mak
Summary: We have achieved the pulsed control of the superlattice effect in two-dimensional materials through the ferroelectric effect, switching between the correlated and superlattice insulating states, and observing the nonlinear anomalous Hall effect. This study demonstrates the potential for creating new functional superlattice materials by incorporating intrinsic symmetry-breaking orders.
NATURE NANOTECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Richen Xiong, Jacob H. Nie, Samuel L. Brantly, Patrick Hays, Renee Sailus, Kenji Watanabe, Takashi Taniguchi, Sefaattin Tongay, Chenhao Jin
Summary: We observe a bosonic correlated insulator composed of excitons in tungsten diselenide/tungsten disulfide (WSe2/WS2) moire superlattices. The insulator transitions continuously into an electron correlated insulator with varying charge density, suggesting a mixed correlated insulating state between the two limits.
Article
Materials Science, Multidisciplinary
Nikodem Sokolowski, Swaroop Palai, Mateusz Dyksik, Katarzyna Posmyk, Michal Baranowski, Alessandro Surrente, Duncan Maude, Felix Carrascoso, Onur Cakiroglu, Estrella Sanchez, Alina Schubert, Carmen Munuera, Takashi Taniguchi, Kenji Watanabe, Joakim Hagel, Samuel Brem, Andres Castellanos-Gomez, Ermin Malic, Paulina Plochocka
Summary: In this study, the influence of twist angle on momentum-indirect excitons (IXs) in a MoSe2/MoS2 heterostructure was investigated using spectroscopy and many-particle theory. It was found that increasing the twist angle led to a significant blue shift of the excitons due to dehybridization. Furthermore, for small twist angle heterostructures, two IX states were observed through photoluminescence measurements, which were attributed to transitions from different moire minibands. This research contributes to a better understanding of the hybridization of momentum-dark IX states influenced by the moire pattern, which is important for applications in moire-tronics and quantum technologies.
Article
Chemistry, Multidisciplinary
Xintong Li, Peng Zhou, Xuan Hu, Ethan Rivers, Kenji Watanabe, Takashi Taniguchi, Deji Akinwande, Joseph S. Friedman, Jean Anne C. Incorvia
Summary: Ambipolar dual-gate transistors based on low-dimensional materials enable reconfigurable logic circuits with suppressed off-state current. This article presents high-performance ambipolar dual-gate transistors based on tungsten diselenide (WSe2), which exhibit high on-off ratio, low off-state current, negligible hysteresis, and ideal subthreshold swing. Cascadable logic gates with minimal static power consumption are demonstrated using these transistors. The study also investigates the behavior of both control gate and polarity gate and analyzes the noise margin and speed performance of the circuits built by dual-gate devices. This work advances the field of ambipolar dual-gate transistors and showcases their potential for low-power, high-speed, and more flexible logic circuits.
Article
Chemistry, Multidisciplinary
Hakon Rost, Simon P. Cooil, Anna Cecilie Asland, Jinbang Hu, Ayaz Ali, Takashi Taniguchi, Kenji Watanabe, Branson D. Belle, Bodil Holst, Jerzy T. Sadowski, Federico Mazzola, Justin W. Wells
Summary: Understanding the collective behavior of quasiparticles in solid-state systems is crucial for nonvolatile electronics, allowing control of many-body effects and their applications. Hexagonal boron nitride (hBN) is a wide-energy-bandgap semiconductor with potential for low-dimensional device heterostructures. Despite its inertness, few-layer hBN shows a significant increase in electron mass, affecting the lifetime of pi-band states. The enhancement is phonon-mediated and has important implications for hBN-based devices.
Article
Chemistry, Physical
Lujun Wang, Sotirios Papadopoulos, Fadil Iyikanat, Jian Zhang, Jing Huang, Takashi Taniguchi, Kenji Watanabe, Michel Calame, Mickael L. Perrin, F. Javier Garcia de Abajo, Lukas Novotny
Summary: The authors demonstrate exciton-assisted resonant electron tunnelling in van der Waals heterostructure tunnel junctions. They reveal tunnelling mechanisms involving indirect or direct excitons and optical emission driven by inelastic electron tunnelling. The study highlights the importance of materials with well-defined interfaces and the potential for van der Waals material-based optoelectronic devices.
Article
Multidisciplinary Sciences
Xin Cong, Parisa Ali Mohammadi, Mingyang Zheng, Kenji Watanabe, Takashi Taniguchi, Daniel Rhodes, Xiao-Xiao Zhang
Summary: The study investigates the characteristics of Fermi sea screening on dark excitons in monolayer WSe2 and its correlation with carrier density. The results indicate that the photoluminescence of dark excitons shows distinct p-doping dependence when the carrier density reaches a critical level.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Lei Ren, Cedric Robert, Hanan Dery, Minhao He, Pengke Li, Dinh Van Tuan, Pierre Renucci, Delphine Lagarde, Takashi Taniguchi, Kenji Watanabe, Xiaodong Xu, Xavier Marie
Summary: We investigated charge tunable devices based on WSe2 and WS2 monolayers encapsulated in hexagonal boron nitride. We observed a weaker-intensity optical transition in photoluminescence measurements when the monolayers were electrostatically doped with electrons. Through a detailed characterization of this photoluminescence line, we identified it as an impurity-assisted radiative recombination of the intervalley negatively charged exciton (triplet trion). Our measurements also revealed the spin-orbit splitting energy difference between the emitted photons from the two possible recombination processes of the same triplet trion.
Article
Chemistry, Multidisciplinary
Tien Dat Ngo, Tuyen Huynh, Inyong Moon, Takashi Taniguchi, Kenji Watanabe, Min Sup Choi, Won Jong Yoo
Summary: This study presents a novel approach to overcome the challenges faced by 2D materials in CMOS technology, specifically in the production of high-performance p-type field effect transistors (p-FETs). By fabricating lateral p+-p-p+ junction WSe2 FETs with self-aligned TG stacks and utilizing selective oxygen plasma-doping, the researchers achieve exceptional electrostatic controllability and low power consumption in PMOS inverters.