1
|
Barrier J, Kim M, Kumar RK, Xin N, Kumaravadivel P, Hague L, Nguyen E, Berdyugin AI, Moulsdale C, Enaldiev VV, Prance JR, Koppens FHL, Gorbachev RV, Watanabe K, Taniguchi T, Glazman LI, Grigorieva IV, Fal'ko VI, Geim AK. One-dimensional proximity superconductivity in the quantum Hall regime. Nature 2024; 628:741-745. [PMID: 38658686 DOI: 10.1038/s41586-024-07271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 03/05/2024] [Indexed: 04/26/2024]
Abstract
Extensive efforts have been undertaken to combine superconductivity and the quantum Hall effect so that Cooper-pair transport between superconducting electrodes in Josephson junctions is mediated by one-dimensional edge states1-6. This interest has been motivated by prospects of finding new physics, including topologically protected quasiparticles7-9, but also extends into metrology and device applications10-13. So far it has proven challenging to achieve detectable supercurrents through quantum Hall conductors2,3,6. Here we show that domain walls in minimally twisted bilayer graphene14-18 support exceptionally robust proximity superconductivity in the quantum Hall regime, allowing Josephson junctions to operate in fields close to the upper critical field of superconducting electrodes. The critical current is found to be non-oscillatory and practically unchanging over the entire range of quantizing fields, with its value being limited by the quantum conductance of ballistic, strictly one-dimensional, electronic channels residing within the domain walls. The system described is unique in its ability to support Andreev bound states at quantizing fields and offers many interesting directions for further exploration.
Collapse
Affiliation(s)
- Julien Barrier
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
| | - Minsoo Kim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- Department of Applied Physics, Kyung Hee University, Yong-in, South Korea
| | - Roshan Krishna Kumar
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Na Xin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- Department of Chemistry, Zhejiang University, Hangzhou, China.
| | - P Kumaravadivel
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Lee Hague
- National Graphene Institute, University of Manchester, Manchester, UK
| | - E Nguyen
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - A I Berdyugin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Christian Moulsdale
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - V V Enaldiev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - J R Prance
- Department of Physics, Lancaster University, Lancaster, UK
| | - F H L Koppens
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - R V Gorbachev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, Japan
| | - L I Glazman
- Department of Physics, Yale University, New Haven, CT, USA
| | - I V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - V I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
| |
Collapse
|
2
|
Srivastav SK, Udupa A, Watanabe K, Taniguchi T, Sen D, Das A. Electric-Field-Tunable Edge Transport in Bernal-Stacked Trilayer Graphene. Phys Rev Lett 2024; 132:096301. [PMID: 38489611 DOI: 10.1103/physrevlett.132.096301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/29/2023] [Accepted: 01/29/2024] [Indexed: 03/17/2024]
Abstract
This Letter presents a nonlocal study on the electric-field-tunable edge transport in h-BN-encapsulated dual-gated Bernal-stacked (ABA) trilayer graphene across various displacement fields (D) and temperatures (T). Our measurements revealed that the nonlocal resistance (R_{NL}) surpassed the expected classical Ohmic contribution by a factor of at least 2 orders of magnitude. Through scaling analysis, we found that the nonlocal resistance scales linearly with the local resistance (R_{L}) only when the D exceeds a critical value of ∼0.2 V/nm. Additionally, we observed that the scaling exponent remains constant at unity for temperatures below the bulk-band gap energy threshold (T<25 K). Further, the value of R_{NL} decreases in a linear fashion as the channel length (L) increases. These experimental findings provide evidence for edge-mediated charge transport in ABA trilayer graphene under the influence of a finite displacement field. Furthermore, our theoretical calculations support these results by demonstrating the emergence of dispersive edge modes within the bulk-band gap energy range when a sufficient displacement field is applied.
Collapse
Affiliation(s)
| | - Adithi Udupa
- Centre for High Energy Physics, Indian Institute of Science, Bangalore 560012, India
| | - K Watanabe
- National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Diptiman Sen
- Centre for High Energy Physics, Indian Institute of Science, Bangalore 560012, India
| | - Anindya Das
- Department of Physics, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
3
|
Abidi E, Khan A, Delgado-Notario JA, Clericó V, Calvo-Gallego J, Taniguchi T, Watanabe K, Otsuji T, Velázquez JE, Meziani YM. Terahertz Detection by Asymmetric Dual Grating Gate Bilayer Graphene FETs with Integrated Bowtie Antenna. Nanomaterials (Basel) 2024; 14:383. [PMID: 38392756 PMCID: PMC10891749 DOI: 10.3390/nano14040383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/03/2024] [Accepted: 02/14/2024] [Indexed: 02/24/2024]
Abstract
An asymmetric dual-grating gate bilayer graphene-based field effect transistor (ADGG-GFET) with an integrated bowtie antenna was fabricated and its response as a Terahertz (THz) detector was experimentally investigated. The device was cooled down to 4.5 K, and excited at different frequencies (0.15, 0.3 and 0.6 THz) using a THz solid-state source. The integration of the bowtie antenna allowed to obtain a substantial increase in the photocurrent response (up to 8 nA) of the device at the three studied frequencies as compared to similar transistors lacking the integrated antenna (1 nA). The photocurrent increase was observed for all the studied values of the bias voltage applied to both the top and back gates. Besides the action of the antenna that helps the coupling of THz radiation to the transistor channel, the observed enhancement by nearly one order of magnitude of the photoresponse is also related to the modulation of the hole and electron concentration profiles inside the transistor channel by the bias voltages imposed to the top and back gates. The creation of local n and p regions leads to the formation of homojuctions (np, pn or pp+) along the channel that strongly affects the overall photoresponse of the detector. Additionally, the bias of both back and top gates could induce an opening of the gap of the bilayer graphene channel that would also contribute to the photocurrent.
Collapse
Affiliation(s)
- E. Abidi
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| | - A. Khan
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| | - J. A. Delgado-Notario
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| | - V. Clericó
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| | - J. Calvo-Gallego
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| | - T. Taniguchi
- National Institute of Material Sciences, 1-1 Namiki, Tsukuba 305-0044, Japan; (T.T.); (K.W.)
| | - K. Watanabe
- National Institute of Material Sciences, 1-1 Namiki, Tsukuba 305-0044, Japan; (T.T.); (K.W.)
| | - T. Otsuji
- Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577, Japan;
| | - J. E. Velázquez
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| | - Y. M. Meziani
- Nanotech Group, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain; (A.K.); (J.A.D.-N.); (V.C.); (J.C.-G.); (J.E.V.)
| |
Collapse
|
4
|
Uto T, Evrard B, Watanabe K, Taniguchi T, Kroner M, İmamoğlu A. Interaction-Induced ac Stark Shift of Exciton-Polaron Resonances. Phys Rev Lett 2024; 132:056901. [PMID: 38364159 DOI: 10.1103/physrevlett.132.056901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 12/20/2023] [Accepted: 01/04/2024] [Indexed: 02/18/2024]
Abstract
Laser-induced shift of atomic states due to the ac Stark effect has played a central role in cold-atom physics and facilitated their emergence as analog quantum simulators. Here, we explore this phenomenon in an atomically thin layer of semiconductor MoSe_{2}, which we embedded in a heterostructure enabling charge tunability. Shining an intense pump laser with a small detuning from the material resonances, we generate a large population of virtual collective excitations and achieve a regime where interactions with this background population are the leading contribution to the ac Stark shift. Using this technique we study how itinerant charges modify-and dramatically enhance-the interactions between optical excitations. In particular, our experiments show that the interaction between attractive polarons could be more than an order of magnitude stronger than those between bare excitons.
Collapse
Affiliation(s)
- T Uto
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - B Evrard
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - K Watanabe
- Research Center for Electronic and Optical Materials, NIMS, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- Research Center for Electronic and Optical Materials, NIMS, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - M Kroner
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - A İmamoğlu
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| |
Collapse
|
5
|
Teraji T, Shinei C, Masuyama Y, Miyakawa M, Taniguchi T. Nitrogen concentration control during diamond growth for NV - centre formation. Philos Trans A Math Phys Eng Sci 2024; 382:20220322. [PMID: 38043575 DOI: 10.1098/rsta.2022.0322] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/25/2023] [Indexed: 12/05/2023]
Abstract
Negatively charged nitrogen-vacancy (NV-) centres formed in diamond crystals are point defects that have potential applications in various quantum devices such as highly sensitive magnetic sensors. To improve the sensitivity of magnetic sensors using NV- centres, it is essential to precisely control the nitrogen concentration in the crystals. In this paper, we demonstrated that nitrogen concentration in diamond can be controlled with high precision for the following two representative growth methods. One is the high-pressure/high-temperature (HPHT) synthesis method and the other is the chemical vapour deposition (CVD) method. The nitrogen concentration of HPHT-grown diamond decreased semi-logarithmically with increasing contents of titanium or aluminium as nitrogen getter materials. The nitrogen concentration of CVD-grown diamond increased linearly with increasing the flow rate ratio of nitrogen to carbon. NV- centres were formed by controlling the total fluence of electron beams so that approximately 20% of the nitrogen became NV- centres. The coherence time of electron spin of NV- centres obtained by the Hahn-echo pulse sequence T2 of these diamond crystals was inversely proportional to the nitrogen concentration. A comparison of T2 of the NV- centres for HPHT-synthesized and CVD-grown diamonds showed no significant difference between them. This article is part of the Theo Murphy meeting issue 'Diamond for quantum applications'.
Collapse
Affiliation(s)
- T Teraji
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - C Shinei
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Y Masuyama
- Quantum Materials and Applications Research Center, National Institutes for Quantum Science and Technology, 1233 Watanuki-machi, Takasaki, Gunma 370-1292, Japan
| | - M Miyakawa
- Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - T Taniguchi
- Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| |
Collapse
|
6
|
Tomomatsu K, Taniguchi T, Hashizume H, Harada T, Iidaka T, Asai Y, Oka H, Muraki S, Akune T, Kawaguchi H, Nakamura K, Yoshida M, Tanaka S, Yoshimura N, Yamada H. Factors associated with cam deformity in Japanese local residents. Sci Rep 2024; 14:1585. [PMID: 38238438 PMCID: PMC10796762 DOI: 10.1038/s41598-024-51876-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 01/10/2024] [Indexed: 01/22/2024] Open
Abstract
Femoroacetabular impingement has increasingly been recognized as a cause of primary hip osteoarthritis; however, its epidemiological indications remain unclear. We aimed to clarify the epidemiological indications and factors associated with cam deformity in a large-scale population-based cohort in Japan. Overall, 1480 participants (2960 hips) (491 men, 989 women; mean age, 65.3 years) analyzed in the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability study were included. The α angle and spinopelvic parameters (lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence) were radiographically measured. Cam deformity was defined as α angle ≥ 60°. Overall, the cam deformity prevalence was 147/2960 (5.0%). Cam deformity prevalence tended to increase with age; in the univariate analysis, a higher percentage of men was observed in the group with cam deformity than in the group without it. No relationship was observed between cam deformity and hip pain. Factors associated with α angle were examined via multiple regression analysis for each gender; α angle was significantly associated with age and BMI in each gender. The α angle and PT were correlated in women. Thus, α angle and cam deformity prevalence increase with age in Japanese individuals. Accordingly, cam deformity can be considered a developmental disease.
Collapse
Affiliation(s)
- Koichi Tomomatsu
- Naga Municipal Hospital, 1282 Uchida, Kinokawa City, Wakayama, Japan
| | - Takaya Taniguchi
- Naga Municipal Hospital, 1282 Uchida, Kinokawa City, Wakayama, Japan.
| | - Hiroshi Hashizume
- School of Health and Nursing Science, Wakayama Medical University, 590 Mikazura, Wakayama City, Wakayama, Japan
| | - Teiji Harada
- Naga Municipal Hospital, 1282 Uchida, Kinokawa City, Wakayama, Japan
| | - Toshiko Iidaka
- Department of Preventive Medicine for Locomotive Organ Disorders, 22nd Century Medical and Research Center, Faculty of Medicine, University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, Japan
| | - Yoshiki Asai
- Department of Orthopaedic Surgery, Wakayama Medical University, 811‑1 Kimiidera, Wakayama City, Wakayama, Japan
| | - Hiroyuki Oka
- Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical &Research Center, Faculty of Medicine, University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, Japan
| | - Shigeyuki Muraki
- Department of Preventive Medicine for Locomotive Organ Disorders, 22nd Century Medical and Research Center, Faculty of Medicine, University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, Japan
| | - Toru Akune
- National Rehabilitation Center for Persons With Disabilities, 4‑1 Namiki, Tokorozawa City, Saitama, Japan
| | | | - Kozo Nakamura
- Department of Orthopaedic Surgery, Towa Hospital, 4‑7‑10 Towa, Adachi‑ku, Tokyo, Japan
| | - Munehito Yoshida
- Department of Orthopaedic Surgery, Sumiya Orthopedic Hospital, 337 Yoshida, Wakayama City, Wakayama, Japan
| | - Sakae Tanaka
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, Japan
| | - Noriko Yoshimura
- Department of Preventive Medicine for Locomotive Organ Disorders, 22nd Century Medical and Research Center, Faculty of Medicine, University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, Japan
| | - Hiroshi Yamada
- Department of Orthopaedic Surgery, Wakayama Medical University, 811‑1 Kimiidera, Wakayama City, Wakayama, Japan
| |
Collapse
|
7
|
Parappurath A, Ghawri B, Bhowmik S, Singha A, Watanabe K, Taniguchi T, Ghosh A. Band structure sensitive photoresponse in twisted bilayer graphene proximitized with WSe 2. Nanoscale 2023; 15:18818-18824. [PMID: 37962416 DOI: 10.1039/d3nr04864k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The ability to tune the twist angle between different layers of two-dimensional (2D) materials has enabled the creation of electronic flat bands artificially, leading to exotic quantum phases. When a twisted blilayer of graphene (tBLG) is placed at the van der Waals proximity to a semiconducting layer of transition metal dichalcogenide (TMDC), such as WSe2, the emergent phases in the tBLG can fundamentally modify the functionality of such heterostructures. Here we have performed photoresponse measurements in few-layer-WSe2/tBLG heterostructure, where the mis-orientation angle of the tBLG layer was chosen to lie close to the magic angle of 1.1°. Our experiments show that the photoresponse is extremely sensitive to the band structure of tBLG and gets strongly suppressed when the Fermi energy was placed within the low-energy moiré bands. Photoresponse could however be recovered when Fermi energy exceeded the moiré band edge where it was dominated by the photogating effect due to transfer of charge between the tBLG and the WSe2 layers. Our observations suggest the possibility of the screening effects from moiré flat bands that strongly affect the charge transfer process at the WSe2/tBLG interface, which is further supported by time-resolved photo-resistance measurements.
Collapse
Affiliation(s)
- Aparna Parappurath
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India.
| | - Bhaskar Ghawri
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India.
| | - Saisab Bhowmik
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, 560012, India
| | - Arup Singha
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India.
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Arindam Ghosh
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India.
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560 012, India
| |
Collapse
|
8
|
Hecker K, Banszerus L, Schäpers A, Möller S, Peters A, Icking E, Watanabe K, Taniguchi T, Volk C, Stampfer C. Coherent charge oscillations in a bilayer graphene double quantum dot. Nat Commun 2023; 14:7911. [PMID: 38036517 PMCID: PMC10689829 DOI: 10.1038/s41467-023-43541-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 11/13/2023] [Indexed: 12/02/2023] Open
Abstract
The coherent dynamics of a quantum mechanical two-level system passing through an anti-crossing of two energy levels can give rise to Landau-Zener-Stückelberg-Majorana (LZSM) interference. LZSM interference spectroscopy has proven to be a fruitful tool to investigate charge noise and charge decoherence in semiconductor quantum dots (QDs). Recently, bilayer graphene has developed as a promising platform to host highly tunable QDs potentially useful for hosting spin and valley qubits. So far, in this system no coherent oscillations have been observed and little is known about charge noise in this material. Here, we report coherent charge oscillations and [Formula: see text] charge decoherence times in a bilayer graphene double QD. The charge decoherence times are measured independently using LZSM interference and photon assisted tunneling. Both techniques yield [Formula: see text] average values in the range of 400-500 ps. The observation of charge coherence allows to study the origin and spectral distribution of charge noise in future experiments.
Collapse
Affiliation(s)
- K Hecker
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany.
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany.
| | - L Banszerus
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - A Schäpers
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
| | - S Möller
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - A Peters
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
| | - E Icking
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - C Volk
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - C Stampfer
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| |
Collapse
|
9
|
Kumar P, Kim H, Tripathy S, Watanabe K, Taniguchi T, Novoselov KS, Kotekar-Patil D. Excited state spectroscopy and spin splitting in single layer MoS 2 quantum dots. Nanoscale 2023; 15:18203-18211. [PMID: 37920920 DOI: 10.1039/d3nr03844k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Semiconducting transition metal dichalcogenides (TMDCs) are very promising materials for quantum dots and spin-qubit implementation. Reliable operation of spin qubits requires the knowledge of the Landé g-factor, which can be measured by exploiting the discrete energy spectrum on a quantum dot. However, the quantum dots realized in TMDCs are yet to reach the required control and quality for reliable measurement of excited state spectroscopy and the g-factor, particularly in atomically thin layers. Quantum dot sizes reported in TMDCs so far are not small enough to observe discrete energy levels on them. Here, we report on electron transport through discrete energy levels of quantum dots in a single layer MoS2 isolated from its environment using a dual gate geometry. The quantum dot energy levels are separated by a few (5-6) meV such that the ground state and the first excited state transitions are clearly visible, thanks to the low contact resistance of ∼700 Ω and relatively low gate voltages. This well-resolved energy separation allowed us to accurately measure the ground state g-factor of ∼5 in MoS2 quantum dots. We observed a spin-filling sequence in our quantum dots under a perpendicular magnetic field. Such a system offers an excellent testbed to measure the key parameters for evaluation and implementation of spin-valley qubits in TMDCs, thus accelerating the development of quantum systems in two-dimensional semiconducting TMDCs.
Collapse
Affiliation(s)
- P Kumar
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, 119077, Singapore
| | - H Kim
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis way, Singapore 138634, Singapore.
| | - S Tripathy
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis way, Singapore 138634, Singapore.
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials, Science, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- Research Center for Functional Materials, National Institute for Materials, Science, Tsukuba, 305-0044, Japan
| | - K S Novoselov
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, 119077, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore.
| | - D Kotekar-Patil
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis way, Singapore 138634, Singapore.
| |
Collapse
|
10
|
Ciorciaro L, Smoleński T, Morera I, Kiper N, Hiestand S, Kroner M, Zhang Y, Watanabe K, Taniguchi T, Demler E, İmamoğlu A. Kinetic magnetism in triangular moiré materials. Nature 2023; 623:509-513. [PMID: 37968525 PMCID: PMC10651480 DOI: 10.1038/s41586-023-06633-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 09/12/2023] [Indexed: 11/17/2023]
Abstract
Magnetic properties of materials ranging from conventional ferromagnetic metals to strongly correlated materials such as cuprates originate from Coulomb exchange interactions. The existence of alternate mechanisms for magnetism that could naturally facilitate electrical control has been discussed theoretically1-7, but an experimental demonstration8 in an extended system has been missing. Here we investigate MoSe2/WS2 van der Waals heterostructures in the vicinity of Mott insulator states of electrons forming a frustrated triangular lattice and observe direct evidence of magnetic correlations originating from a kinetic mechanism. By directly measuring electronic magnetization through the strength of the polarization-selective attractive polaron resonance9,10, we find that when the Mott state is electron-doped, the system exhibits ferromagnetic correlations in agreement with the Nagaoka mechanism.
Collapse
Affiliation(s)
- L Ciorciaro
- Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland
| | - T Smoleński
- Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland
| | - I Morera
- Departament de Física Quàntica i Astrofísica, Facultat de Física, Universitat de Barcelona, Barcelona, Spain
- Institut de Ciències del Cosmos, Universitat de Barcelona, Barcelona, Spain
| | - N Kiper
- Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland
| | - S Hiestand
- Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland
| | - M Kroner
- Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland
| | - Y Zhang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, USA
- Min H. Kao Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA
| | - K Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan
| | - T Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - E Demler
- Institute for Theoretical Physics, ETH Zürich, Zürich, Switzerland
| | - A İmamoğlu
- Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland.
| |
Collapse
|
11
|
Kozaki T, Minamide A, Taniguchi T, Taniguchi W, Nishiyama D, Tamai H, Yamada H. Life-threatening necrotizing fasciitis after spinal surgery with electromyography monitoring and intravenous access at lower limb: A case report. J Orthop Sci 2023; 28:1505-1507. [PMID: 34625326 DOI: 10.1016/j.jos.2021.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 08/01/2021] [Accepted: 08/16/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Takuhei Kozaki
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan.
| | - Akihito Minamide
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan
| | - Takaya Taniguchi
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan
| | - Wataru Taniguchi
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan
| | - Daisuke Nishiyama
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan
| | - Hidenobu Tamai
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan
| | - Hiroshi Yamada
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan
| |
Collapse
|
12
|
Montanaro A, Piccinini G, Mišeikis V, Sorianello V, Giambra MA, Soresi S, Giorgi L, D'Errico A, Watanabe K, Taniguchi T, Pezzini S, Coletti C, Romagnoli M. Sub-THz wireless transmission based on graphene-integrated optoelectronic mixer. Nat Commun 2023; 14:6471. [PMID: 37833246 PMCID: PMC10575943 DOI: 10.1038/s41467-023-42194-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
Optoelectronics is a valuable solution to scale up wireless links frequency to sub-THz in the next generation antenna systems and networks. Here, we propose a low-power consumption, small footprint building block for 6 G and 5 G new radio wireless transmission allowing broadband capacity (e.g., 10-100 Gb/s per link and beyond). We demonstrate a wireless datalink based on graphene, reaching setup limited sub-THz carrier frequency and multi-Gbit/s data rate. Our device consists of a graphene-based integrated optoelectronic mixer capable of mixing an optically generated reference oscillator approaching 100 GHz, with a baseband electrical signal. We report >96 GHz optoelectronic bandwidth and -44 dB upconversion efficiency with a footprint significantly smaller than those of state-of-the-art photonic transmitters (i.e., <0.1 mm2). These results are enabled by an integrated-photonic technology based on wafer-scale high-mobility graphene and pave the way towards the development of optoelectronics-based arrayed-antennas for millimeter-wave technology.
Collapse
Affiliation(s)
- Alberto Montanaro
- Photonic Networks and Technologies Lab - CNIT, Via G. Moruzzi,1, 56124, Pisa, Italy.
- TeCIP Institute, Scuola Superiore Sant'Anna, via G. Moruzzi 1, 56124, Pisa, Italy.
| | - Giulia Piccinini
- NEST, Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, Italy
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127, Pisa, Italy
| | - Vaidotas Mišeikis
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127, Pisa, Italy
- Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Vito Sorianello
- Photonic Networks and Technologies Lab - CNIT, Via G. Moruzzi,1, 56124, Pisa, Italy
| | - Marco A Giambra
- Inphotec, CamGraPhIC srl, via G. Moruzzi 1, 56124, Pisa, Italy
| | - Stefano Soresi
- Inphotec, CamGraPhIC srl, via G. Moruzzi 1, 56124, Pisa, Italy
| | - Luca Giorgi
- Ericsson Research, via G. Moruzzi 1, 56124, Pisa, Italy
| | | | - K Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Sergio Pezzini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, P.zza S. Silvestro 12, 56127, Pisa, Italy
| | - Camilla Coletti
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127, Pisa, Italy
- Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Marco Romagnoli
- Photonic Networks and Technologies Lab - CNIT, Via G. Moruzzi,1, 56124, Pisa, Italy
| |
Collapse
|
13
|
Slot MR, Maximenko Y, Haney PM, Kim S, Walkup DT, Strelcov E, Le ST, Shih EM, Yildiz D, Blankenship SR, Watanabe K, Taniguchi T, Barlas Y, Zhitenev NB, Ghahari F, Stroscio JA. A quantum ruler for orbital magnetism in moiré quantum matter. Science 2023; 382:81-87. [PMID: 37797004 DOI: 10.1126/science.adf2040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 08/30/2023] [Indexed: 10/07/2023]
Abstract
For almost a century, magnetic oscillations have been a powerful "quantum ruler" for measuring Fermi surface topology. In this study, we used Landau-level spectroscopy to unravel the energy-resolved valley-contrasting orbital magnetism and large orbital magnetic susceptibility that contribute to the energies of Landau levels of twisted double-bilayer graphene. These orbital magnetism effects led to substantial deviations from the standard Onsager relation, which manifested as a breakdown in scaling of Landau-level orbits. These substantial magnetic responses emerged from the nontrivial quantum geometry of the electronic structure and the large length scale of the moiré lattice potential. Going beyond traditional measurements, Landau-level spectroscopy performed with a scanning tunneling microscope offers a complete quantum ruler that resolves the full energy dependence of orbital magnetic properties in moiré quantum matter.
Collapse
Affiliation(s)
- M R Slot
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Physics, Georgetown University, Washington, DC 20007, USA
| | - Y Maximenko
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - P M Haney
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - S Kim
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Joint Quantum Institute, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - D T Walkup
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - E Strelcov
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Son T Le
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - E M Shih
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - D Yildiz
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Joint Quantum Institute, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - S R Blankenship
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Y Barlas
- Department of Physics, University of Nevada, Reno, NV 89557, USA
| | - N B Zhitenev
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - F Ghahari
- Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA
| | - J A Stroscio
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| |
Collapse
|
14
|
Tanaka O, Taniguchi T, Ono K, Kiryu T, Makita C, Matsuo M. Evaluation of Liver Functionality after Liver Stereotactic Body Radiation Therapy (SBRT) Using Blood Tests and Imaging Examinations. Int J Radiat Oncol Biol Phys 2023; 117:e343. [PMID: 37785196 DOI: 10.1016/j.ijrobp.2023.06.2407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Several studies have shown that liver function can be evaluated after hepatic stereotactic body radiation therapy (SBRT) using galactosyl human serum albumin (GSA) liver scintigraphy and Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI). However, there are no reports investigating the relationship (including Chile-Pugh classification) between imaging and blood tests. Therefore, we investigated the changes that occur in the liver between before and after SBRT by combining imaging (GSA, computed tomography (CT), and MRI) with blood tests that assess total liver function (albumin-bilirubin (ALBI) grade, ICG-R15). We decided to find a method that could assess liver reserve capacity locally and globally MATERIALS/METHODS: Of the 23 patients who underwent hepatic SBRT, 12 patients underwent GSA, MRI, and ICG-R15 testing before treatment, 1 month after treatment, and 3 months after treatment. All patients underwent imaging studies and blood tests at the beginning of treatment, 1 month after treatment, and 3 months after treatment ended. The evaluation items were as follows: 1) changes over time in Child-Pugh classification, ICG-R15, and ALBI values before and after SBRT; 2) changes over time in GSA count and ICG; and 3) selection of the optimal sequence for recognizing radiation hepatitis on MRI. RESULTS The ICG values were 14.4 before RT, 17.1 after 1 month, and 17.6 after 3 months. ICG worsened after 1 month of treatment, but was similar after 3 months. ALBI values were -2.61 before RT, -2.67 after 1 month, and -2.71 after 3 months. ALBl worsened slightly over time. CONCLUSION Regarding the ICG-R15, there was an average worsening of 2.8 after 1 month of treatment compared with before SBRT, but only of 0.5 between 1 month and 3 months after SBRT. Therefore, evaluation using ICG-R15 after SBRT after 1 month alone may be sufficient.
Collapse
Affiliation(s)
- O Tanaka
- Asahi University Hospital, Department of Radiation Oncology, Gifu, Japan
| | - T Taniguchi
- Department of Radiology, Frontier Science for imaging, Gifu University, Gifu, Japan
| | - K Ono
- Department of Radiology, Gifu University Japan, Gifu, Japan
| | - T Kiryu
- Asahi University Hospital, Hashimoto-Cho, Gifu city, Gifu, Japan
| | - C Makita
- Gifu University Hospital, Gifu, Japan
| | - M Matsuo
- Gifu University School of Medicine, Department of Radiology, Gifu, Japan
| |
Collapse
|
15
|
Kozaki T, Hashizume H, Tsutsui S, Takami M, Taniguchi T, Yamada H. Acetabular Rim Fracture after Adult Spinal Deformity Surgery-Induced Secondary Hip Osteoarthritis: Two Case Reports. Spine Surg Relat Res 2023; 7:464-467. [PMID: 37841040 PMCID: PMC10569802 DOI: 10.22603/ssrr.2023-0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/20/2023] [Indexed: 10/17/2023] Open
Affiliation(s)
- Takuhei Kozaki
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Hiroshi Hashizume
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Shunji Tsutsui
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Masanari Takami
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Takaya Taniguchi
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Hiroshi Yamada
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan
| |
Collapse
|
16
|
Ren L, Robert C, Glazov M, Semina M, Amand T, Lombez L, Lagarde D, Taniguchi T, Watanabe K, Marie X. Control of the Bright-Dark Exciton Splitting Using the Lamb Shift in a Two-Dimensional Semiconductor. Phys Rev Lett 2023; 131:116901. [PMID: 37774277 DOI: 10.1103/physrevlett.131.116901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 07/19/2023] [Indexed: 10/01/2023]
Abstract
We investigate the exciton fine structure in atomically thin WSe_{2}-based van der Waals heterostructures where the density of optical modes at the location of the semiconductor monolayer can be tuned. The energy splitting Δ between the bright and dark exciton is measured by photoluminescence spectroscopy. We demonstrate that Δ can be tuned by a few meV as a result of a significant Lamb shift of the optically active exciton that arises from emission and absorption of virtual photons triggered by the vacuum fluctuations of the electromagnetic field. We also measure strong variations of the bright exciton radiative linewidth as a result of the Purcell effect. All these experimental results illustrate the strong sensitivity of the excitons to local vacuum field fluctuations. We find a very good agreement with a model that demonstrates the equivalence, for our system, of a classical electrodynamical transfer matrix formalism and quantum-electrodynamical approach. The bright-dark splitting control we demonstrate here in the weak light-matter coupling regime should apply to any semiconductor structures.
Collapse
Affiliation(s)
- L Ren
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - C Robert
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - M Glazov
- Ioffe Institute, 26 Polytechnicheskaya, 194021 Saint Petersburg, Russia
| | - M Semina
- Ioffe Institute, 26 Polytechnicheskaya, 194021 Saint Petersburg, Russia
| | - T Amand
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - L Lombez
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Lagarde
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - X Marie
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| |
Collapse
|
17
|
Taniguchi T, Timmerman D, Ichikawa S, Tatebayashi J, Fujiwara Y. Electrically driven europium-doped GaN microdisk. Opt Lett 2023; 48:4590-4592. [PMID: 37656562 DOI: 10.1364/ol.494616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 08/05/2023] [Indexed: 09/03/2023]
Abstract
For the practical implementation of microdisk resonators as active nanophotonic devices, it is essential that they can be electrically driven. However, it is difficult to inject current in such small-scale devices without severely degrading their optical properties. We demonstrate the successful fabrication of an electrically injected microdisk based on Eu-doped GaN, in which an SiO2 spacer is used to prevent the interaction of the metal contact with the optical resonances. The microdisk shows Eu-related emission upon electrical injection and from the observed resonance peak, a cavity quality (Q)-factor of 3400 is concluded.
Collapse
|
18
|
Del Águila AG, Wong YR, Wadgaonkar I, Fieramosca A, Liu X, Vaklinova K, Dal Forno S, Do TTH, Wei HY, Watanabe K, Taniguchi T, Novoselov KS, Koperski M, Battiato M, Xiong Q. Ultrafast exciton fluid flow in an atomically thin MoS 2 semiconductor. Nat Nanotechnol 2023; 18:1012-1019. [PMID: 37524907 DOI: 10.1038/s41565-023-01438-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/01/2023] [Indexed: 08/02/2023]
Abstract
Excitons (coupled electron-hole pairs) in semiconductors can form collective states that sometimes exhibit spectacular nonlinear properties. Here, we show experimental evidence of a collective state of short-lived excitons in a direct-bandgap, atomically thin MoS2 semiconductor whose propagation resembles that of a classical liquid as suggested by the nearly uniform photoluminescence through the MoS2 monolayer regardless of crystallographic defects and geometric constraints. The exciton fluid flows over ultralong distances (at least 60 μm) at a speed of ~1.8 × 107 m s-1 (~6% the speed of light). The collective phase emerges above a critical laser power, in the absence of free charges and below a critical temperature (usually Tc ≈ 150 K) approaching room temperature in hexagonal-boron-nitride-encapsulated devices. Our theoretical simulations suggest that momentum is conserved and local equilibrium is achieved among excitons; both these features are compatible with a fluid dynamics description of the exciton transport.
Collapse
Affiliation(s)
- Andrés Granados Del Águila
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Yi Ren Wong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Indrajit Wadgaonkar
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Antonio Fieramosca
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Xue Liu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, P.R. China
| | - Kristina Vaklinova
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore
| | - Stefano Dal Forno
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - T Thu Ha Do
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Ho Yi Wei
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, Japan
| | - Kostya S Novoselov
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore
| | - Maciej Koperski
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore
| | - Marco Battiato
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Qihua Xiong
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, P.R. China.
- Frontier Science Center for Quantum Information, Beijing, P.R. China.
- Collaborative Innovation Center of Quantum Matter, Beijing, P.R. China.
- Beijing Academy of Quantum Information Sciences, Beijing, P.R. China.
| |
Collapse
|
19
|
Bhowmik S, Ghawri B, Park Y, Lee D, Datta S, Soni R, Watanabe K, Taniguchi T, Ghosh A, Jung J, Chandni U. Spin-orbit coupling-enhanced valley ordering of malleable bands in twisted bilayer graphene on WSe 2. Nat Commun 2023; 14:4055. [PMID: 37422470 DOI: 10.1038/s41467-023-39855-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 06/26/2023] [Indexed: 07/10/2023] Open
Abstract
Recent experiments in magic-angle twisted bilayer graphene have revealed a wealth of novel electronic phases as a result of interaction-driven spin-valley flavour polarisation. In this work, we investigate correlated phases due to the combined effect of spin-orbit coupling-enhanced valley polarisation and the large density of states below half filling of the moiré band in twisted bilayer graphene coupled to tungsten diselenide. We observe an anomalous Hall effect, accompanied by a series of Lifshitz transitions that are highly tunable with carrier density and magnetic field. The magnetisation shows an abrupt change of sign near half-filling, confirming its orbital nature. While the Hall resistance is not quantised at zero magnetic fields-indicating a ground state with partial valley polarisation-perfect quantisation and complete valley polarisation are observed at finite fields. Our results illustrate that singularities in the flat bands in the presence of spin-orbit coupling can stabilise ordered phases even at non-integer moiré band fillings.
Collapse
Affiliation(s)
- Saisab Bhowmik
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, 560012, India.
| | - Bhaskar Ghawri
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India
| | - Youngju Park
- Department of Physics, University of Seoul, Seoul, 02504, Korea
| | - Dongkyu Lee
- Department of Physics, University of Seoul, Seoul, 02504, Korea
- Department of Smart Cities, University of Seoul, Seoul, 02504, Korea
| | - Suvronil Datta
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, 560012, India
| | - Radhika Soni
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, 560012, India
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki, 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki, 305-0044, Japan
| | - Arindam Ghosh
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Jeil Jung
- Department of Physics, University of Seoul, Seoul, 02504, Korea.
- Department of Smart Cities, University of Seoul, Seoul, 02504, Korea.
| | - U Chandni
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, 560012, India.
| |
Collapse
|
20
|
Banszerus L, Möller S, Hecker K, Icking E, Watanabe K, Taniguchi T, Hassler F, Volk C, Stampfer C. Particle-hole symmetry protects spin-valley blockade in graphene quantum dots. Nature 2023:10.1038/s41586-023-05953-5. [PMID: 37138084 DOI: 10.1038/s41586-023-05953-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/14/2023] [Indexed: 05/05/2023]
Abstract
Particle-hole symmetry plays an important role in the characterization of topological phases in solid-state systems1. It is found, for example, in free-fermion systems at half filling and it is closely related to the notion of antiparticles in relativistic field theories2. In the low-energy limit, graphene is a prime example of a gapless particle-hole symmetric system described by an effective Dirac equation3,4 in which topological phases can be understood by studying ways to open a gap by preserving (or breaking) symmetries5,6. An important example is the intrinsic Kane-Mele spin-orbit gap of graphene, which leads to a lifting of the spin-valley degeneracy and renders graphene a topological insulator in a quantum spin Hall phase7 while preserving particle-hole symmetry. Here we show that bilayer graphene allows the realization of electron-hole double quantum dots that exhibit near-perfect particle-hole symmetry, in which transport occurs via the creation and annihilation of single electron-hole pairs with opposite quantum numbers. Moreover, we show that particle-hole symmetric spin and valley textures lead to a protected single-particle spin-valley blockade. The latter will allow robust spin-to-charge and valley-to-charge conversion, which are essential for the operation of spin and valley qubits.
Collapse
Affiliation(s)
- L Banszerus
- JARA-FIT and 2nd Institute of Physics A, RWTH Aachen University, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, Germany
| | - S Möller
- JARA-FIT and 2nd Institute of Physics A, RWTH Aachen University, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, Germany
| | - K Hecker
- JARA-FIT and 2nd Institute of Physics A, RWTH Aachen University, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, Germany
| | - E Icking
- JARA-FIT and 2nd Institute of Physics A, RWTH Aachen University, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, Germany
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - F Hassler
- JARA-Institute for Quantum Information, RWTH Aachen University, Aachen, Germany
| | - C Volk
- JARA-FIT and 2nd Institute of Physics A, RWTH Aachen University, Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, Germany
| | - C Stampfer
- JARA-FIT and 2nd Institute of Physics A, RWTH Aachen University, Aachen, Germany.
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, Germany.
| |
Collapse
|
21
|
Díez-Mérida J, Díez-Carlón A, Yang SY, Xie YM, Gao XJ, Senior J, Watanabe K, Taniguchi T, Lu X, Higginbotham AP, Law KT, Efetov DK. Symmetry-broken Josephson junctions and superconducting diodes in magic-angle twisted bilayer graphene. Nat Commun 2023; 14:2396. [PMID: 37100775 PMCID: PMC10133447 DOI: 10.1038/s41467-023-38005-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/06/2023] [Indexed: 04/28/2023] Open
Abstract
The coexistence of gate-tunable superconducting, magnetic and topological orders in magic-angle twisted bilayer graphene provides opportunities for the creation of hybrid Josephson junctions. Here we report the fabrication of gate-defined symmetry-broken Josephson junctions in magic-angle twisted bilayer graphene, where the weak link is gate-tuned close to the correlated insulator state with a moiré filling factor of υ = -2. We observe a phase-shifted and asymmetric Fraunhofer pattern with a pronounced magnetic hysteresis. Our theoretical calculations of the junction weak link-with valley polarization and orbital magnetization-explain most of these unconventional features. The effects persist up to the critical temperature of 3.5 K, with magnetic hysteresis observed below 800 mK. We show how the combination of magnetization and its current-induced magnetization switching allows us to realise a programmable zero-field superconducting diode. Our results represent a major advance towards the creation of future superconducting quantum electronic devices.
Collapse
Affiliation(s)
- J Díez-Mérida
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - A Díez-Carlón
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - S Y Yang
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - Y-M Xie
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - X-J Gao
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - J Senior
- IST Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - X Lu
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | | | - K T Law
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Dmitri K Efetov
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain.
| |
Collapse
|
22
|
Grzeszczyk M, Acharya S, Pashov D, Chen Z, Vaklinova K, van Schilfgaarde M, Watanabe K, Taniguchi T, Novoselov KS, Katsnelson MI, Koperski M. Strongly Correlated Exciton-Magnetization System for Optical Spin Pumping in CrBr 3 and CrI 3 . Adv Mater 2023; 35:e2209513. [PMID: 36787625 DOI: 10.1002/adma.202209513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 01/13/2023] [Indexed: 05/17/2023]
Abstract
Ferromagnetism in van der Waals systems, preserved down to a monolayer limit, attracted attention to a class of materials with general composition CrX3 (X=I, Br, and Cl), which are treated now as canonical 2D ferromagnets. Their diverse magnetic properties, such as different easy axes or varying and controllable character of in-plane or interlayer ferromagnetic coupling, make them promising candidates for spintronic, photonic, optoelectronic, and other applications. Still, significantly different magneto-optical properties between the three materials have been presenting a challenging puzzle for researchers over the last few years. Herewith, it is demonstrated that despite similar structural and magnetic configurations, the coupling between excitons and magnetization is qualitatively different in CrBr3 and CrI3 films. Through a combination of the optical spin pumping experiments with the state-of-the-art theory describing bound excitonic states in the presence of magnetization, we concluded that the hole-magnetization coupling has the opposite sign in CrBr3 and CrI3 and also between the ground and excited exciton state. Consequently, efficient spin pumping capabilities are demonstrated in CrBr3 driven by magnetization via spin-dependent absorption, and the different origins of the magnetic hysteresis in CrBr3 and CrI3 are unraveled.
Collapse
Affiliation(s)
- M Grzeszczyk
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
| | - S Acharya
- Institute for Molecules and Materials, Radboud University, AJ Nijmegen, NL-6525, The Netherlands
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - D Pashov
- King's College London, Theory and Simulation of Condensed Matter, The Strand, London, WC2R 2LS, UK
| | - Z Chen
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
| | - K Vaklinova
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
| | - M van Schilfgaarde
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
- King's College London, Theory and Simulation of Condensed Matter, The Strand, London, WC2R 2LS, UK
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - K S Novoselov
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - M I Katsnelson
- Institute for Molecules and Materials, Radboud University, AJ Nijmegen, NL-6525, The Netherlands
| | - M Koperski
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| |
Collapse
|
23
|
Tanaka O, Taniguchi T, Kiryu T, Matsuo M. P090 Dosimetric Evaluation of the Heart and Left Anterior Descending Artery Dose in Radiotherapy for Japanese patients with Breast Cancer. Breast 2023. [DOI: 10.1016/s0960-9776(23)00207-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
|
24
|
Charaev I, Bandurin DA, Bollinger AT, Phinney IY, Drozdov I, Colangelo M, Butters BA, Taniguchi T, Watanabe K, He X, Medeiros O, Božović I, Jarillo-Herrero P, Berggren KK. Single-photon detection using high-temperature superconductors. Nat Nanotechnol 2023; 18:343-349. [PMID: 36941357 DOI: 10.1038/s41565-023-01325-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
The detection of individual quanta of light is important for quantum communication, fluorescence lifetime imaging, remote sensing and more. Due to their high detection efficiency, exceptional signal-to-noise ratio and fast recovery times, superconducting-nanowire single-photon detectors (SNSPDs) have become a critical component in these applications. However, the operation of conventional SNSPDs requires costly cryocoolers. Here we report the fabrication of two types of high-temperature superconducting nanowires. We observe linear scaling of the photon count rate on the radiation power at the telecommunications wavelength of 1.5 μm and thereby reveal single-photon operation. SNSPDs made from thin flakes of Bi2Sr2CaCu2O8+δ exhibit a single-photon response up to 25 K, and for SNSPDs from La1.55Sr0.45CuO4/La2CuO4 bilayer films, this response is observed up to 8 K. While the underlying detection mechanism is not fully understood yet, our work expands the family of materials for SNSPD technology beyond the liquid helium temperature limit and suggests that even higher operation temperatures may be reached using other high-temperature superconductors.
Collapse
Affiliation(s)
- I Charaev
- Massachusetts Institute of Technology, Cambridge, MA, USA.
- University of Zurich, Zurich, Switzerland.
| | - D A Bandurin
- Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore.
| | | | - I Y Phinney
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - I Drozdov
- Brookhaven National Laboratory, Upton, NY, USA
| | - M Colangelo
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - B A Butters
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute of Material Science, Tsukuba, Japan
| | - X He
- Brookhaven National Laboratory, Upton, NY, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - O Medeiros
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - I Božović
- Brookhaven National Laboratory, Upton, NY, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
| | | | - K K Berggren
- Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
25
|
Kozaki T, Hashizume H, Oka H, Ohashi S, Kumano Y, Yamamoto E, Minamide A, Yukawa Y, Iwasaki H, Tsutsui S, Takami M, Nakata K, Taniguchi T, Fukui D, Nishiyama D, Yamanaka M, Tamai H, Taiji R, Murata S, Murata A, Yamada H. Erratum for Lumbar Fusion including Sacroiliac Joint Fixation Increases the Stress and Angular Motion at the Hip Joint: A Finite Element Study. Spine Surg Relat Res 2023; 7:199. [PMID: 37041871 PMCID: PMC10083080 DOI: 10.22603/ssrr.2021-0231-er] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 02/02/2023] [Indexed: 03/28/2023] Open
Abstract
[This corrects the article DOI: 10.22603/ssrr.2021-0231.].
Collapse
|
26
|
Parto K, Azzam SI, Lewis N, Patel SD, Umezawa S, Watanabe K, Taniguchi T, Moody G. Cavity-Enhanced 2D Material Quantum Emitters Deterministically Integrated with Silicon Nitride Microresonators. Nano Lett 2022; 22:9748-9756. [PMID: 36318636 PMCID: PMC9756340 DOI: 10.1021/acs.nanolett.2c03151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/26/2022] [Indexed: 05/25/2023]
Abstract
Optically active defects in 2D materials, such as hexagonal boron nitride (hBN) and transition-metal dichalcogenides (TMDs), are an attractive class of single-photon emitters with high brightness, operation up to room temperature, site-specific engineering of emitter arrays with strain and irradiation techniques, and tunability with external electric fields. In this work, we demonstrate a novel approach to precisely align and embed hBN and TMDs within background-free silicon nitride microring resonators. Through the Purcell effect, high-purity hBN emitters exhibit a cavity-enhanced spectral coupling efficiency of up to 46% at room temperature, exceeding the theoretical limit (up to 40%) for cavity-free waveguide-emitter coupling and demonstrating nearly a 1 order of magnitude improvement over previous work. The devices are fabricated with a CMOS-compatible process and exhibit no degradation of the 2D material optical properties, robustness to thermal annealing, and 100 nm positioning accuracy of quantum emitters within single-mode waveguides, opening a path for scalable quantum photonic chips with on-demand single-photon sources.
Collapse
Affiliation(s)
- K. Parto
- Electrical
and Computer Engineering Department, University
of California, Santa
Barbara, California93106, United States
| | - S. I. Azzam
- Electrical
and Computer Engineering Department, University
of California, Santa
Barbara, California93106, United States
- California
Nanosystems Institute, University of California, Santa Barbara, California93106, United States
| | - N. Lewis
- Electrical
and Computer Engineering Department, University
of California, Santa
Barbara, California93106, United States
| | - S. D. Patel
- Electrical
and Computer Engineering Department, University
of California, Santa
Barbara, California93106, United States
| | - S. Umezawa
- Electrical
and Computer Engineering Department, University
of California, Santa
Barbara, California93106, United States
| | - K. Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba305-0044, Japan
| | - T. Taniguchi
- International
Center for Materials Nanoarchitectures, National Institute for Materials Science, 1-1 Namiki, Tsukuba305-0044, Japan
| | - G. Moody
- Electrical
and Computer Engineering Department, University
of California, Santa
Barbara, California93106, United States
- California
Nanosystems Institute, University of California, Santa Barbara, California93106, United States
| |
Collapse
|
27
|
Bandurin DA, Principi A, Phinney IY, Taniguchi T, Watanabe K, Jarillo-Herrero P. Interlayer Electron-Hole Friction in Tunable Twisted Bilayer Graphene Semimetal. Phys Rev Lett 2022; 129:206802. [PMID: 36461999 DOI: 10.1103/physrevlett.129.206802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/22/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
Charge-neutral conducting systems represent a class of materials with unusual properties governed by electron-hole (e-h) interactions. Depending on the quasiparticle statistics, band structure, and device geometry these semimetallic phases of matter can feature unconventional responses to external fields that often defy simple interpretations in terms of single-particle physics. Here we show that small-angle twisted bilayer graphene (SA TBG) offers a highly tunable system in which to explore interactions-limited electron conduction. By employing a dual-gated device architecture we tune our devices from a nondegenerate charge-neutral Dirac fluid to a compensated two-component e-h Fermi liquid where spatially separated electrons and holes experience strong mutual friction. This friction is revealed through the T^{2} resistivity that accurately follows the e-h drag theory we develop. Our results provide a textbook illustration of a smooth transition between different interaction-limited transport regimes and clarify the conduction mechanisms in charge-neutral SA TBG.
Collapse
Affiliation(s)
- D A Bandurin
- Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore
| | - A Principi
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - I Y Phinney
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba 305-0044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute of Material Science, Tsukuba 305-0044, Japan
| | - P Jarillo-Herrero
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| |
Collapse
|
28
|
Tanaka O, Taniguchi T, Ono K, Matsubara M, Matsuo M. 253P Hemostatic radiotherapy for gastric cancer: MRI as an alternative to endoscopy for post-treatment evaluation. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.10.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
|
29
|
Kozaki T, Hashizume H, Taniguchi T, Nishiyama D, Iwasaki H, Tsutsui S, Takami M, Nagata K, Fukui D, Yamanaka M, Tamai H, Taiji R, Murata S, Oka H, Yamada H. S2 alar-iliac screw loosening as a preventive factor for hip joint osteoarthritis after adult spinal deformity surgery: a case-control study. Eur Spine J 2022; 31:3081-3088. [PMID: 35999305 DOI: 10.1007/s00586-022-07344-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 06/12/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
PURPOSE This study aimed to evaluate the progression of hip pathology and risk factors after ASD surgery. METHODS This case-control study enrolled 123 patients (246 hips); seven hips underwent hip arthroplasty were excluded. We measured the center-edge (CE) angle, joint space width (JSW), and Kellgren-Lawrence (KL) grade. We defined a CE angle˂25° as developmental dysplasia of the hip (DDH). We evaluated S2 alar-iliac (AI) screw loosening at final follow-up. RESULTS The annual decrease in the JSW was 0.31 mm up to 1 year, and 0.13 mm after 1 year (p = 0.001). KL grade progression occurred in 24 hips (10.0%; group P), while no progression occurred in 215 (90.0%; group N) hips. Nonparametric analysis between groups P and N revealed that significant differences were observed in sex, DDH, KL grade, ratio of S2AI screw fixation at baseline, and ratio of S2AI screw loosening at final follow-up. Multiple logistic regression analysis revealed that DDH (p = 0.018, odds ratio (OR) = 3.0, 95%CI = 1.2-7.3), baseline KL grade (p < 0.0001, OR = 37.7, 95%CI = 7.0-203.2), and S2AI screw fixation (p = 0.035, OR = 3.4, 95%CI = 1.1-10.4) were significant factors. We performed sub-analysis to elucidate the relationship between screw loosening and hip osteoarthritis in 131 hips that underwent S2AI screw fixation. Non-loosening of the S2AI screw was a significant factor for KL grade progression (p < 0.0001, OR = 8.9, 95%CI = 3.0-26.4). CONCLUSION This study identified the prevalence and risk factors for the progression of hip osteoarthritis after ASD surgery. Physicians need to pay attention to the hip joint pathology after ASD surgery.
Collapse
Affiliation(s)
- Takuhei Kozaki
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Hiroshi Hashizume
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan.
- School of Health and Nursing Science, Wakayama Medical University, 580 Mikazura, Wakayama City, Japan.
| | - Takaya Taniguchi
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Daisuke Nishiyama
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Hiroshi Iwasaki
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Shunji Tsutsui
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Masanari Takami
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Keiji Nagata
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Daisuke Fukui
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Manabu Yamanaka
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Hidenobu Tamai
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Ryo Taiji
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Shizumasa Murata
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| | - Hiroyuki Oka
- Department of Medical Research and Management for Musculoskeletal Pain, 22Nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Hiroshi Yamada
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Japan
| |
Collapse
|
30
|
Sano M, Toyota T, Morimoto T, Okada T, Sasaki Y, Taniguchi T, Kim K, Kobori A, Ehara N, Kinoshita M, Doi A, Tomii K, Kihara Y, Furukawa Y. Prediction of clinical outcomes in patients with coronavirus disease 2019 using high-sensitive troponin I and N-terminal pro-B-type natriuretic peptide. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Several comorbidities, including cardiovascular diseases or myocardial injury, are reported to be associated with poor prognosis in patients with Coronavirus disease 2019 (COVID-19). However, detailed prognostic analysis of myocardial injury by various biomarkers in COVID-19 patients is limited.
Purpose
This study aims to explore the prognostic values of high-sensitive Troponin I (hsTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) for COVID-19 patients using Japanese real-world data.
Methods
The COVID-MI study is a retrospective cohort study that enrolls consecutive laboratory-confirmed COVID-19 patients admitted to the hospital from July 2020 to September 2021. We collected clinical data, including cardiac biomarker values, by chart review. If the prespecified biomarkers in concern were not available, we measured them using the institutional serum blood bank, which enrolled patients prospectively from July 2020. Patients with available biomarkers were analyzed according to the values of hsTnI or NT-proBNP, using the clinically relevant thresholds (hsTnI: 5 ng/L and 99th percentile of the upper reference limit [99%ile URL], and NT-proBNP: 125 pg/mL and 900 pg/mL). The primary outcome measure was all-cause death. Secondary outcome measures included acute respiratory distress syndrome, myocardial infarction, myocarditis/pericarditis, venous thromboembolism, cerebral infarction, and bleeding events.
Results
We enrolled 917 patients with COVID-19 confirmed by viral nucleic acid amplification test. The mean age was 61 years, and 591 patients (64%) were men. On admission, the number of patients classified as severe or critical COVID-19 was 515 (56%) and 85 (8.7%), respectively. Among the 544 patients with hsTnI values, 365 (67%) patients had elevated hsTnI of ≥5 ng/L, and 134 patients (25%) had TnI of ≥99%ile URL. Besides, among 546 patients with NT-proBNP values, 295 patients (54%) had elevated NT-pro-BNP of ≥125 pg/mL, and 93 patients (17%) had NT-proBNP of ≥900 pg/mL. The median follow-up period was 31 days (interquartile range: 11–90 days). In cumulative incidence analysis, higher levels of hsTnI and NT-proBNP were associated with significantly higher mortality (hsTnI: <5 ng/L group; 8.8%, 5 ng/L to 99%ile URL group; 19%, and ≥99%ile URL group; 37%, P<0.001, and NT-proBNP: <125 pg/mL group; 7.8%, 125 to 900 pg/mL group; 21%, and ≥900 pg/mL group; 45%, P<0.001). The adjusted risk for all-cause death remained significant for each threshold of cardiac biomarkers (hsTnI ≥99%ile URL: hazard ratio [HR] 1.98, 95% confidence interval [CI] 1.11–3.54, P=0.02, and NT-proBNP ≥900 pg/mL: HR 3.60, 95% CI 1.86–6.98, P<0.001).
Conclusion
Elevation of hsTnI or NT-proBNP was associated with poor prognosis in the current relatively severely ill COVID-19 patients. Measuring hsTnI or NT-proBNP can be an attractive option for risk stratification and deciding appropriate management in patients with COVID-19.
Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): Institutional Research Fund at Kobe City Medical Center General Hospital
Collapse
Affiliation(s)
- M Sano
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - T Toyota
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - T Morimoto
- Kobe City Medical Center General Hospital, Center for Clinical Research and Innovation , Kobe , Japan
| | - T Okada
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - Y Sasaki
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - T Taniguchi
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - K Kim
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - A Kobori
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - N Ehara
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - M Kinoshita
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| | - A Doi
- Kobe City Medical Center General Hospital, Department of Infectious Diseases , Kobe , Japan
| | - K Tomii
- Kobe City Medical Center General Hospital, Department of Respiratory Medicine , Kobe , Japan
| | - Y Kihara
- Kobe City Medical Center General Hospital , Kobe , Japan
| | - Y Furukawa
- Kobe City Medical Center General Hospital, Department of Cardiovascular Medicine , Kobe , Japan
| |
Collapse
|
31
|
Jo M, Lee JYM, Assouline A, Brasseur P, Watanabe K, Taniguchi T, Roche P, Glattli DC, Kumada N, Parmentier FD, Sim HS, Roulleau P. Scaling behavior of electron decoherence in a graphene Mach-Zehnder interferometer. Nat Commun 2022; 13:5473. [PMID: 36115841 PMCID: PMC9482640 DOI: 10.1038/s41467-022-33078-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 08/30/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractOver the past 20 years, many efforts have been made to understand and control decoherence in 2D electron systems. In particular, several types of electronic interferometers have been considered in GaAs heterostructures, in order to protect the interfering electrons from decoherence. Nevertheless, it is now understood that several intrinsic decoherence sources fundamentally limit more advanced quantum manipulations. Here, we show that graphene offers a unique possibility to reach a regime where the decoherence is frozen and to study unexplored regimes of electron interferometry. We probe the decoherence of electron channels in a graphene quantum Hall PN junction, forming a Mach-Zehnder interferometer1,2, and unveil a scaling behavior of decay of the interference visibility with the temperature scaled by the interferometer length. It exhibits a remarkable crossover from an exponential decay at higher temperature to an algebraic decay at lower temperature where almost no decoherence occurs, a regime previously unobserved in GaAs interferometers.
Collapse
|
32
|
Le Breton G, Delagrange R, Hong Y, Garg M, Watanabe K, Taniguchi T, Ribeiro-Palau R, Roulleau P, Roche P, Parmentier FD. Heat Equilibration of Integer and Fractional Quantum Hall Edge Modes in Graphene. Phys Rev Lett 2022; 129:116803. [PMID: 36154417 DOI: 10.1103/physrevlett.129.116803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/01/2022] [Indexed: 06/16/2023]
Abstract
Hole-conjugate states of the fractional quantum Hall effect host counterpropagating edge channels which are thought to exchange charge and energy. These exchanges have been the subject of extensive theoretical and experimental works; in particular, it is yet unclear if the presence of integer quantum Hall edge channels stemming from fully filled Landau levels affects heat equilibration along the edge. In this Letter, we present heat transport measurements in quantum Hall states of graphene demonstrating that the integer channels can strongly equilibrate with the fractional ones, leading to markedly different regimes of quantized heat transport that depend on edge electrostatics. Our results allow for a better comprehension of the complex edge physics in the fractional quantum Hall regime.
Collapse
Affiliation(s)
- G Le Breton
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette cedex, France
| | - R Delagrange
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette cedex, France
| | - Y Hong
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120 Palaiseau, France
| | - M Garg
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette cedex, France
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, 305-0044 Tsukuba, Japan
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, 305-0044 Tsukuba, Japan
| | - R Ribeiro-Palau
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120 Palaiseau, France
| | - P Roulleau
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette cedex, France
| | - P Roche
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette cedex, France
| | - F D Parmentier
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette cedex, France
| |
Collapse
|
33
|
Kumar C, Birkbeck J, Sulpizio JA, Perello D, Taniguchi T, Watanabe K, Reuven O, Scaffidi T, Stern A, Geim AK, Ilani S. Imaging hydrodynamic electrons flowing without Landauer-Sharvin resistance. Nature 2022; 609:276-281. [PMID: 36071191 DOI: 10.1038/s41586-022-05002-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 06/21/2022] [Indexed: 11/09/2022]
Abstract
Electrical resistance usually originates from lattice imperfections. However, even a perfect lattice has a fundamental resistance limit, given by the Landauer1 conductance caused by a finite number of propagating electron modes. This resistance, shown by Sharvin2 to appear at the contacts of electronic devices, sets the ultimate conduction limit of non-interacting electrons. Recent years have seen growing evidence of hydrodynamic electronic phenomena3-18, prompting recent theories19,20 to ask whether an electronic fluid can radically break the fundamental Landauer-Sharvin limit. Here, we use single-electron-transistor imaging of electronic flow in high-mobility graphene Corbino disk devices to answer this question. First, by imaging ballistic flows at liquid-helium temperatures, we observe a Landauer-Sharvin resistance that does not appear at the contacts but is instead distributed throughout the bulk. This underpins the phase-space origin of this resistance-as emerging from spatial gradients in the number of conduction modes. At elevated temperatures, by identifying and accounting for electron-phonon scattering, we show the details of the purely hydrodynamic flow. Strikingly, we find that electron hydrodynamics eliminates the bulk Landauer-Sharvin resistance. Finally, by imaging spiralling magneto-hydrodynamic Corbino flows, we show the key emergent length scale predicted by hydrodynamic theories-the Gurzhi length. These observations demonstrate that electronic fluids can dramatically transcend the fundamental limitations of ballistic electrons, with important implications for fundamental science and future technologies.
Collapse
Affiliation(s)
- C Kumar
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - J Birkbeck
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - J A Sulpizio
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - D Perello
- School of Physics & Astronomy, University of Manchester, Manchester, UK.,National Graphene Institute, University of Manchester, Manchester, UK
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, Japan
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - O Reuven
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - T Scaffidi
- Department of Physics, University of Toronto, Toronto, ON, Canada.,Department of Physics and Astronomy, University of California, Irvine, CA, USA
| | - Ady Stern
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - A K Geim
- School of Physics & Astronomy, University of Manchester, Manchester, UK.,National Graphene Institute, University of Manchester, Manchester, UK
| | - S Ilani
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel.
| |
Collapse
|
34
|
Ren L, Lombez L, Robert C, Beret D, Lagarde D, Urbaszek B, Renucci P, Taniguchi T, Watanabe K, Crooker SA, Marie X. Optical Detection of Long Electron Spin Transport Lengths in a Monolayer Semiconductor. Phys Rev Lett 2022; 129:027402. [PMID: 35867459 DOI: 10.1103/physrevlett.129.027402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Using a spatially resolved optical pump-probe experiment, we measure the lateral transport of spin-valley polarized electrons over very long distances (tens of micrometers) in a single WSe_{2} monolayer. By locally pumping the Fermi sea of 2D electrons to a high degree of spin-valley polarization (up to 75%) using circularly polarized light, the lateral diffusion of the electron polarization can be mapped out via the photoluminescence induced by a spatially separated and linearly polarized probe laser. Up to 25% spin-valley polarization is observed at pump-probe separations up to 20 μm. Characteristic spin-valley diffusion lengths of 18±3 μm are revealed at low temperatures. The dependence on temperature, pump helicity, pump intensity, and electron density highlight the key roles played by spin relaxation time and pumping efficiency on polarized electron transport in monolayer semiconductors possessing spin-valley locking.
Collapse
Affiliation(s)
- L Ren
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - L Lombez
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - C Robert
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Beret
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Lagarde
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - B Urbaszek
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - P Renucci
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - S A Crooker
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - X Marie
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| |
Collapse
|
35
|
Karpińska M, Jasiński J, Kempt R, Ziegler JD, Sansom H, Taniguchi T, Watanabe K, Snaith HJ, Surrente A, Dyksik M, Maude DK, Kłopotowski Ł, Chernikov A, Kuc A, Baranowski M, Plochocka P. Interlayer excitons in MoSe 2/2D perovskite hybrid heterostructures - the interplay between charge and energy transfer. Nanoscale 2022; 14:8085-8095. [PMID: 35611659 DOI: 10.1039/d2nr00877g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
van der Waals crystals have opened a new and exciting chapter in heterostructure research, removing the lattice matching constraint characteristics of epitaxial semiconductors. They provide unprecedented flexibility for heterostructure design. Combining two-dimensional (2D) perovskites with other 2D materials, in particular transition metal dichalcogenides (TMDs), has recently emerged as an intriguing way to design hybrid opto-electronic devices. However, the excitation transfer mechanism between the layers (charge or energy transfer) remains to be elucidated. Here, we investigate PEA2PbI4/MoSe2 and (BA)2PbI4/MoSe2 heterostructures by combining optical spectroscopy and density functional theory (DFT) calculations. We show that band alignment facilitates charge transfer. Namely, holes are transferred from TMDs to 2D perovskites, while the electron transfer is blocked, resulting in the formation of interlayer excitons. Moreover, we show that the energy transfer mechanism can be turned on by an appropriate alignment of the excitonic states, providing a rule of thumb for the deterministic control of the excitation transfer mechanism in TMD/2D-perovskite heterostructures.
Collapse
Affiliation(s)
- M Karpińska
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
- Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland
| | - J Jasiński
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - R Kempt
- Technische Universität Dresden, Bergstr. 66c, 01062 Dresden, Germany
| | - J D Ziegler
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
| | - H Sansom
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - H J Snaith
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - A Surrente
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - M Dyksik
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - D K Maude
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
| | - Ł Kłopotowski
- Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland
| | - A Chernikov
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062 Dresden, Germany
| | - A Kuc
- Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, 04318 Leipzig, Germany.
| | - M Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| | - P Plochocka
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France.
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland.
| |
Collapse
|
36
|
Tanaka O, Yagi N, Tawada M, Taniguchi T, Adachi K, Nakaya S, Makita C, Matsuo M. PO-1296 Hemostatic Radiotherapy for Gastric Cancer: Relationship Between MR Images and Tumor Markers. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)03260-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
37
|
Ohno C, Ogawa T, Taniguchi T, Kinoshita T, Fujita Y, Nishimura Y, Yamada H, Tajima F. Effect of 3-week preoperative rehabilitation on pain and daily physical activities in patients with severe osteoarthritis undergoing total knee arthroplasty. Br J Pain 2022; 16:472-480. [PMID: 36389013 PMCID: PMC9644108 DOI: 10.1177/20494637221084190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background We hypothesized that 3 weeks of preoperative rehabilitation could improve
postoperative pain in patients undergoing total knee arthroplasty (TKA).
Aim: This study aimed to evaluate the effects of 3 weeks of preoperative
rehabilitation on postoperative pain after TKA. Methods This prospective cohort study included 29 subjects (41 knees) divided into
two groups: the preoperative rehabilitation group included 14 subjects (20
knees) and the control group included 15 subjects (21 knees). All subjects
were scheduled for unilateral or bilateral TKA. The preoperative
rehabilitation group completed a 90-min rehabilitation program 3 days per
week for 3 weeks before their TKA. The rehabilitation included body weight
exercise, resistance exercise, and cycle ergometer exercise. The control
group did not undergo any rehabilitation prior to TKA. We assessed the
patients using Western Ontario and McMaster Universities’ Osteoarthritis
Index (WOMAC) and recorded their physical activity of walking, standing,
sitting, and lying down at study entry and/or before TKA and 1 month after
TKA. Results The WOMAC total and WOMAC pain scores were significantly lower after 3-weeks
of rehabilitation, but before TKA and 1 month after surgery were
significantly lower in the preoperative rehabilitation group than in the
control group. The time spent walking, standing, sitting, and lying down for
12 h did not change after TKA in the preoperative rehabilitation group. In
contrast, in the control group, the time spent in walking and standing
positions decreased and the time in the sitting position increased after TKA
(p < 0.05). Conclusion: We found that 3-week preoperative training
reduced knee pain and helped maintain physical activity after surgery in
patients with severe osteoarthritis who underwent TKA.
Collapse
Affiliation(s)
- Chigusa Ohno
- Department of Rehabilitation Medicine, Gifu Municipal Hospital, Gifu, Japan
| | - Takahiro Ogawa
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
- Chuzan Hospital Clinical Education and Research Center, Okinawa, Japan
| | - Takaya Taniguchi
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Tokio Kinoshita
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | - Yasuhisa Fujita
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | - Yukihide Nishimura
- Department of Rehabilitation Medicine, Iwate Medical University, Morioka, Japan
| | - Hiroshi Yamada
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Fumihiro Tajima
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| |
Collapse
|
38
|
Kozaki T, Hashizume H, Oka H, Ohashi S, Kumano Y, Yamamoto E, Minamide A, Yukawa Y, Iwasaki H, Tsutsui S, Takami M, Nakata K, Taniguchi T, Fukui D, Nishiyama D, Yamanaka M, Tamai H, Taiji R, Murata S, Murata A, Yamada H. Lumbar Fusion including Sacroiliac Joint Fixation Increases the Stress and Angular Motion at the Hip Joint: A Finite Element Study. Spine Surg Relat Res 2022; 6:681-688. [PMID: 36561150 PMCID: PMC9747219 DOI: 10.22603/ssrr.2021-0231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/14/2022] [Indexed: 12/25/2022] Open
Abstract
Introduction Adult spinal fusion surgery improves lumbar alignment and patient satisfaction. Adult spinal deformity surgery improves saggital balance not only lumbar lesion, but also at hip joint coverage. It was expected that hip joint coverage rate was improved and joint stress decreased. However, it was reported that adjacent joint disease at hip joint was induced by adult spinal fusion surgery including sacroiliac joint fixation on an X-ray study. The mechanism is still unclear. We aimed to investigate the association between lumbosacral fusion including sacroiliac joint fixation and contact stress of the hip joint. Methods A 40-year-old woman with intact lumbar vertebrae underwent computed tomography. A three-dimensional nonlinear finite element model was constructed from the L4 vertebra to the femoral bone with triangular shell elements (thickness, 2 mm; size, 3 mm) for the cortical bone's outer surface and 2-mm (lumbar spine) or 3-mm (femoral bone) tetrahedral solid elements for the remaining bone. We constructed the following four models: a non-fusion model (NF), a L4-5 fusion model (L5F), a L4-S1 fusion model (S1F), and a L4-S2 alar iliac screw fixation model (S2F). A compressive load of 400 N was applied vertically to the L4 vertebra and a 10-Nm bending moment was additionally applied to the L4 vertebra to stimulate flexion, extension, left lateral bending, and axial rotation. Each model's hip joint's von Mises stress and angular motion were analyzed. Results The hip joint's angular motion in NF, L5F, S1F, and S2F gradually increased; the S2F model presented the greatest angular motion. Conclusions The average and maximum contact stress of the hip joint was the highest in the S2F model. Thus, lumbosacral fusion surgery with sacroiliac joint fixation placed added stress on the hip joint. We propose that this was a consequence of adjacent joint spinopelvic fixation. Lumbar-to-pelvic fixation increases the angular motion and stress at the hip joint.
Collapse
Affiliation(s)
- Takuhei Kozaki
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Hiroshi Hashizume
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Hiroyuki Oka
- Department of Medical Research and Management for Musculoskeletal Pain, Faculty of Medicine, 22nd Century Medical and Research Center, The University of Tokyo, Tokyo, Japan
| | - Satoru Ohashi
- Department of Orthopaedic Surgery, Sagamihara Hospital, National Hospital Organization, Sagamihara, Kanagawa, Japan
| | - Yoh Kumano
- Department of Spine Surgery, Tokyo Yamate Medical Center, Japan Community Healthcare Organization, Tokyo, Japan
| | - Ei Yamamoto
- Department of Biomedical Engineering, Faculty of Biology-Oriented Science and Technology, KinDai University, Kinokawa, Wakayama, Japan
| | - Akihito Minamide
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Yasutsugu Yukawa
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Hiroshi Iwasaki
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Shunji Tsutsui
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Masanari Takami
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Keiji Nakata
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Takaya Taniguchi
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Daisuke Fukui
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Daisuke Nishiyama
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Manabu Yamanaka
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Hidenobu Tamai
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Ryo Taiji
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Shizumasa Murata
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Akimasa Murata
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| | - Hiroshi Yamada
- Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan
| |
Collapse
|
39
|
Turkel S, Swann J, Zhu Z, Christos M, Watanabe K, Taniguchi T, Sachdev S, Scheurer MS, Kaxiras E, Dean CR, Pasupathy AN. Orderly disorder in magic-angle twisted trilayer graphene. Science 2022; 376:193-199. [PMID: 35389784 DOI: 10.1126/science.abk1895] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Magic-angle twisted trilayer graphene (TTG) has recently emerged as a platform to engineer strongly correlated flat bands. We reveal the normal-state structural and electronic properties of TTG using low-temperature scanning tunneling microscopy at twist angles for which superconductivity has been observed. Real trilayer samples undergo a strong reconstruction of the moiré lattice, which locks layers into near-magic-angle, mirror symmetric domains comparable in size with the superconducting coherence length. This relaxation introduces an array of localized twist-angle faults, termed twistons and moiré solitons, whose electronic structure deviates strongly from the background regions, leading to a doping-dependent, spatially granular electronic landscape. The Fermi-level density of states is maximally uniform at dopings for which superconductivity has been observed in transport measurements.
Collapse
Affiliation(s)
- Simon Turkel
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Joshua Swann
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Ziyan Zhu
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Maine Christos
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Subir Sachdev
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.,School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540, USA
| | - Mathias S Scheurer
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Efthimios Kaxiras
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.,John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Cory R Dean
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Abhay N Pasupathy
- Department of Physics, Columbia University, New York, NY 10027, USA.,Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| |
Collapse
|
40
|
Smoleński T, Watanabe K, Taniguchi T, Kroner M, Imamoğlu A. Spin-Valley Relaxation and Exciton-Induced Depolarization Dynamics of Landau-Quantized Electrons in MoSe_{2} Monolayer. Phys Rev Lett 2022; 128:127402. [PMID: 35394309 DOI: 10.1103/physrevlett.128.127402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/05/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Nonequilibrium dynamics of strongly correlated systems constitutes a fascinating problem of condensed matter physics with many open questions. Here, we investigate the relaxation dynamics of Landau-quantized electron system into spin-valley polarized ground state in a gate-tunable MoSe_{2} monolayer subjected to a strong magnetic field. The system is driven out of equilibrium with optically injected excitons that depolarize the electron spins and the subsequent electron spin-valley relaxation is probed in time-resolved experiments. We demonstrate that both the relaxation and light-induced depolarization rates at millikelvin temperatures sensitively depend on the Landau level filling factor: the relaxation is enhanced whenever the electrons form an integer quantum Hall liquid and slows down appreciably at noninteger fillings, while the depolarization rate exhibits an opposite behavior. Our findings suggest that spin-valley dynamics may be used as a tool to investigate the interplay between the effects of disorder and strong interactions in the electronic ground state.
Collapse
Affiliation(s)
- T Smoleński
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - M Kroner
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - A Imamoğlu
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| |
Collapse
|
41
|
Berdyugin AI, Xin N, Gao H, Slizovskiy S, Dong Z, Bhattacharjee S, Kumaravadivel P, Xu S, Ponomarenko LA, Holwill M, Bandurin DA, Kim M, Cao Y, Greenaway MT, Novoselov KS, Grigorieva IV, Watanabe K, Taniguchi T, Fal'ko VI, Levitov LS, Kumar RK, Geim AK. Out-of-equilibrium criticalities in graphene superlattices. Science 2022; 375:430-433. [PMID: 35084955 DOI: 10.1126/science.abi8627] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy, whereas the filled bands underneath contribute little to conduction. Here, we describe a very different regime in which carrier distribution in graphene and its superlattices is shifted so far from equilibrium that the filled bands start playing an essential role, leading to a critical-current behavior. The criticalities develop upon the velocity of electron flow reaching the Fermi velocity. Key signatures of the out-of-equilibrium state are current-voltage characteristics that resemble those of superconductors, sharp peaks in differential resistance, sign reversal of the Hall effect, and a marked anomaly caused by the Schwinger-like production of hot electron-hole plasma. The observed behavior is expected to be common to all graphene-based superlattices.
Collapse
Affiliation(s)
- Alexey I Berdyugin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Na Xin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Haoyang Gao
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sergey Slizovskiy
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Zhiyu Dong
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shubhadeep Bhattacharjee
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - P Kumaravadivel
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Shuigang Xu
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - L A Ponomarenko
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,Department of Physics, University of Lancaster, Lancaster LA1 4YW, UK
| | - Matthew Holwill
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - D A Bandurin
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Minsoo Kim
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - Yang Cao
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - M T Greenaway
- Department of Physics, Loughborough University, Loughborough LE11 3TU, UK.,School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - K S Novoselov
- National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| | - I V Grigorieva
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - V I Fal'ko
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK.,Henry Royce Institute for Advanced Materials, Manchester M13 9PL, UK
| | - L S Levitov
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Roshan Krishna Kumar
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK.,Institut de Ciencies Fotoniques (ICFO), Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - A K Geim
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.,National Graphene Institute, University of Manchester, Manchester M13 9PL, UK
| |
Collapse
|
42
|
Lin JX, Zhang YH, Morissette E, Wang Z, Liu S, Rhodes D, Watanabe K, Taniguchi T, Hone J, Li JIA. Spin-orbit-driven ferromagnetism at half moiré filling in magic-angle twisted bilayer graphene. Science 2022; 375:437-441. [PMID: 34990215 DOI: 10.1126/science.abh2889] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Strong electron correlation and spin-orbit coupling (SOC) can have a profound influence on the electronic properties of materials. We examined their combined influence on a two-dimensional electronic system at the atomic interface between magic-angle twisted bilayer graphene and a tungsten diselenide crystal. We found that strong electron correlation within the moiré flatband stabilizes correlated insulating states at both quarter and half filling, and that SOC transforms these Mott-like insulators into ferromagnets, as evidenced by a robust anomalous Hall effect with hysteretic switching behavior. The coupling between spin and valley degrees of freedom could be demonstrated through control of the magnetic order with an in-plane magnetic field or a perpendicular electric field. Our findings establish an experimental knob to engineer topological properties of moiré bands in twisted bilayer graphene and related systems.
Collapse
Affiliation(s)
- Jiang-Xiazi Lin
- Department of Physics, Brown University, Providence, RI 02912, USA
| | - Ya-Hui Zhang
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Erin Morissette
- Department of Physics, Brown University, Providence, RI 02912, USA
| | - Zhi Wang
- Department of Physics, Brown University, Providence, RI 02912, USA
| | - Song Liu
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - Daniel Rhodes
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - J I A Li
- Department of Physics, Brown University, Providence, RI 02912, USA
| |
Collapse
|
43
|
Kumar R, Srivastav SK, Spånslätt C, Watanabe K, Taniguchi T, Gefen Y, Mirlin AD, Das A. Observation of ballistic upstream modes at fractional quantum Hall edges of graphene. Nat Commun 2022; 13:213. [PMID: 35017473 PMCID: PMC8752686 DOI: 10.1038/s41467-021-27805-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 12/07/2021] [Indexed: 11/27/2022] Open
Abstract
The presence of "upstream" modes, moving against the direction of charge current flow in the fractional quantum Hall (FQH) phases, is critical for the emergence of renormalized modes with exotic quantum statistics. Detection of excess noise at the edge is a smoking gun for the presence of upstream modes. Here, we report noise measurements at the edges of FQH states realized in dual graphite-gated bilayer graphene devices. A noiseless dc current is injected at one of the edge contacts, and the noise generated at contacts at length, L = 4 μm and 10 μm away along the upstream direction is studied. For integer and particle-like FQH states, no detectable noise is measured. By contrast, for "hole-conjugate" FQH states, we detect a strong noise proportional to the injected current, unambiguously proving the existence of upstream modes. The noise magnitude remains independent of length, which matches our theoretical analysis demonstrating the ballistic nature of upstream energy transport, quite distinct from the diffusive propagation reported earlier in GaAs-based systems.
Collapse
Affiliation(s)
- Ravi Kumar
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India
| | | | - Christian Spånslätt
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, S-412 96, Göteborg, Sweden
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
| | - K Watanabe
- National Institute of Material Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- National Institute of Material Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Yuval Gefen
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Alexander D Mirlin
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
- Petersburg Nuclear Physics Institute, 188300, St. Petersburg, Russia
- L. D. Landau Institute for Theoretical Physics RAS, 119334, Moscow, Russia
| | - Anindya Das
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India.
| |
Collapse
|
44
|
Möller S, Banszerus L, Knothe A, Steiner C, Icking E, Trellenkamp S, Lentz F, Watanabe K, Taniguchi T, Glazman LI, Fal'ko VI, Volk C, Stampfer C. Probing Two-Electron Multiplets in Bilayer Graphene Quantum Dots. Phys Rev Lett 2021; 127:256802. [PMID: 35029428 DOI: 10.1103/physrevlett.127.256802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 11/01/2021] [Indexed: 05/21/2023]
Abstract
We report on finite bias spectroscopy measurements of the two-electron spectrum in a gate defined bilayer graphene (BLG) quantum dot for varying magnetic fields. The spin and valley degree of freedom in BLG give rise to multiplets of six orbital symmetric and ten orbital antisymmetric states. We find that orbital symmetric states are lower in energy and separated by ≈ 0.4-0.8 meV from orbital antisymmetric states. The symmetric multiplet exhibits an additional energy splitting of its six states of ≈ 0.15-0.5 meV due to lattice scale interactions. The experimental observations are supported by theoretical calculations, which allow to determine that intervalley scattering and "current-current" interaction constants are of the same magnitude in BLG.
Collapse
Affiliation(s)
- S Möller
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen 52074, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich 52425, Germany
| | - L Banszerus
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen 52074, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich 52425, Germany
| | - A Knothe
- National Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
| | - C Steiner
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen 52074, Germany
| | - E Icking
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen 52074, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich 52425, Germany
| | - S Trellenkamp
- Helmholtz Nano Facility, Forschungszentrum Jülich, Jülich 52425, Germany
| | - F Lentz
- Helmholtz Nano Facility, Forschungszentrum Jülich, Jülich 52425, Germany
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - L I Glazman
- Departments of Physics and Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - V I Fal'ko
- National Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester M13 9PL, United Kingdom
| | - C Volk
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen 52074, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich 52425, Germany
| | - C Stampfer
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen 52074, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich 52425, Germany
| |
Collapse
|
45
|
Vallejo Bustamante J, Wu NJ, Fermon C, Pannetier-Lecoeur M, Wakamura T, Watanabe K, Taniguchi T, Pellegrin T, Bernard A, Daddinounou S, Bouchiat V, Guéron S, Ferrier M, Montambaux G, Bouchiat H. Detection of graphene's divergent orbital diamagnetism at the Dirac point. Science 2021; 374:1399-1402. [PMID: 34882473 DOI: 10.1126/science.abf9396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- J Vallejo Bustamante
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - N J Wu
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.,Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France
| | - C Fermon
- SPEC, CEA, CNRS, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | | | - T Wakamura
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.,NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Pellegrin
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - A Bernard
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - S Daddinounou
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - V Bouchiat
- Néel Institute, CNRS, 38000 Grenoble, France
| | - S Guéron
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - M Ferrier
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - G Montambaux
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - H Bouchiat
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| |
Collapse
|
46
|
Taniguchi T, Hyodo F, Ichikawa K, Shimozato T, Ono K, Nakaya S, Tanaka O, Matsuo M. Usefulness of an Image-Based Noise-Reduction Technique in Cone Beam Computed Tomography for Adaptive Radiotherapy. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
47
|
Tanaka O, Taniguchi T, Ono K, Nakaya S, Makita C, Kiryu T, Matsuo M. Adrenal Stereotactic Body Radiation Therapy: The Effects of a Full and Empty Stomach on Radiation Dose to Organs at Risk. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.1333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
48
|
Arita S, Nishiyama D, Taniguchi T, Fukui D, Yamanaka M, Yamada H. Feature selection to classify lameness using a smartphone-based inertial measurement unit. PLoS One 2021; 16:e0258067. [PMID: 34591946 PMCID: PMC8483374 DOI: 10.1371/journal.pone.0258067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/16/2021] [Indexed: 11/24/2022] Open
Abstract
Background and objectives Gait can be severely affected by pain, muscle weakness, and aging resulting in lameness. Despite the high incidence of lameness, there are no studies on the features that are useful for classifying lameness patterns. Therefore, we aimed to identify features of high importance for classifying population differences in lameness patterns using an inertial measurement unit mounted above the sacral region. Methods Features computed exhaustively for multidimensional time series consisting of three-axis angular velocities and three-axis acceleration were carefully selected using the Benjamini–Yekutieli procedure, and multiclass classification was performed using LightGBM (Microsoft Corp., Redmond, WA, USA). We calculated the relative importance of the features that contributed to the classification task in machine learning. Results The most important feature was found to be the absolute value of the Fourier coefficients of the second frequency calculated by the one-dimensional discrete Fourier transform for real input. This was determined by the fast Fourier transformation algorithm using data of a single gait cycle of the yaw angular velocity of the pelvic region. Conclusions Using an inertial measurement unit worn over the sacral region, we determined a set of features of high importance for classifying differences in lameness patterns based on different factors. This completely new set of indicators can be used to advance the understanding of lameness.
Collapse
Affiliation(s)
- Satoshi Arita
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Daisuke Nishiyama
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
- * E-mail:
| | - Takaya Taniguchi
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Daisuke Fukui
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Manabu Yamanaka
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Hiroshi Yamada
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| |
Collapse
|
49
|
Moore SL, Ciccarino CJ, Halbertal D, McGilly LJ, Finney NR, Yao K, Shao Y, Ni G, Sternbach A, Telford EJ, Kim BS, Rossi SE, Watanabe K, Taniguchi T, Pasupathy AN, Dean CR, Hone J, Schuck PJ, Narang P, Basov DN. Nanoscale lattice dynamics in hexagonal boron nitride moiré superlattices. Nat Commun 2021; 12:5741. [PMID: 34593793 PMCID: PMC8484559 DOI: 10.1038/s41467-021-26072-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 09/02/2021] [Indexed: 11/12/2022] Open
Abstract
Twisted two-dimensional van der Waals (vdW) heterostructures have unlocked a new means for manipulating the properties of quantum materials. The resulting mesoscopic moiré superlattices are accessible to a wide variety of scanning probes. To date, spatially-resolved techniques have prioritized electronic structure visualization, with lattice response experiments only in their infancy. Here, we therefore investigate lattice dynamics in twisted layers of hexagonal boron nitride (hBN), formed by a minute twist angle between two hBN monolayers assembled on a graphite substrate. Nano-infrared (nano-IR) spectroscopy reveals systematic variations of the in-plane optical phonon frequencies amongst the triangular domains and domain walls in the hBN moiré superlattices. Our first-principles calculations unveil a local and stacking-dependent interaction with the underlying graphite, prompting symmetry-breaking between the otherwise identical neighboring moiré domains of twisted hBN. Here, the authors investigate the lattice dynamics of twisted hexagonal boron nitride layers via nano-infrared spectroscopy, showing local and stacking-dependent variations of the optical phonon frequencies associated to the interaction with the graphite substrate.
Collapse
Affiliation(s)
- S L Moore
- Department of Physics, Columbia University, New York, NY, USA.
| | - C J Ciccarino
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - D Halbertal
- Department of Physics, Columbia University, New York, NY, USA
| | - L J McGilly
- Department of Physics, Columbia University, New York, NY, USA
| | - N R Finney
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - K Yao
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Y Shao
- Department of Physics, Columbia University, New York, NY, USA
| | - G Ni
- Department of Physics, Columbia University, New York, NY, USA
| | - A Sternbach
- Department of Physics, Columbia University, New York, NY, USA
| | - E J Telford
- Department of Physics, Columbia University, New York, NY, USA
| | - B S Kim
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - S E Rossi
- Department of Physics, Columbia University, New York, NY, USA
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - A N Pasupathy
- Department of Physics, Columbia University, New York, NY, USA
| | - C R Dean
- Department of Physics, Columbia University, New York, NY, USA
| | - J Hone
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - P J Schuck
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - P Narang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - D N Basov
- Department of Physics, Columbia University, New York, NY, USA
| |
Collapse
|
50
|
Nishiyama D, Iwasaki H, Taniguchi T, Fukui D, Yamanaka M, Harada T, Yamada H. Deep generative models for automated muscle segmentation in computed tomography scanning. PLoS One 2021; 16:e0257371. [PMID: 34506602 PMCID: PMC8432798 DOI: 10.1371/journal.pone.0257371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/28/2021] [Indexed: 11/18/2022] Open
Abstract
Accurate gluteus medius (GMd) volume evaluation may aid in the analysis of muscular atrophy states and help gain an improved understanding of patient recovery via rehabilitation. However, the segmentation of muscle regions in GMd images for cubic muscle volume assessment is time-consuming and labor-intensive. This study automated GMd-region segmentation from the computed tomography (CT) images of patients diagnosed with hip osteoarthritis using deep learning and evaluated the segmentation accuracy. To this end, 5250 augmented pairs of training data were obtained from five participants, and a conditional generative adversarial network was used to identify the relationships between the image pairs. Using the preserved test datasets, the results of automatic segmentation with the trained deep learning model were compared to those of manual segmentation in terms of the dice similarity coefficient (DSC), volume similarity (VS), and shape similarity (MS). As observed, the average DSC values for automatic and manual segmentations were 0.748 and 0.812, respectively, with a significant difference (p < 0.0001); the average VS values were 0.247 and 0.203, respectively, with no significant difference (p = 0.069); and the average MS values were 1.394 and 1.156, respectively, with no significant difference (p = 0.308). The GMd volumes obtained by automatic and manual segmentation were 246.2 cm3 and 282.9 cm3, respectively. The noninferiority of the DSC obtained by automatic segmentation was verified against that obtained by manual segmentation. Accordingly, the proposed GAN-based automatic GMd-segmentation technique is confirmed to be noninferior to manual segmentation. Therefore, the findings of this research confirm that the proposed method not only reduces time and effort but also facilitates accurate assessment of the cubic muscle volume.
Collapse
Affiliation(s)
- Daisuke Nishiyama
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
- * E-mail:
| | - Hiroshi Iwasaki
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Takaya Taniguchi
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Daisuke Fukui
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Manabu Yamanaka
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Teiji Harada
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| | - Hiroshi Yamada
- Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan
| |
Collapse
|