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de Oliveira TG, Fox-Rosales LA, Ramírez-Fernández JD, Cepeda-Duque JC, Zug R, Sanchez-Lalinde C, Oliveira MJR, Marinho PHD, Bonilla-Sánchez A, Marques MC, Cassaro K, Moreno R, Rumiz D, Peters FB, Ortega J, Cavalcanti G, Mooring MS, Blankenship SR, Brenes-Mora E, Dias D, Mazim FD, Eizirik E, Diehl JL, Marques RV, Ribeiro ACC, Cruz RA, Pasa E, Meira LPC, Pereira A, Ferreira GB, de Pinho FF, Sena LMM, de Morais VR, Ribeiro Luiz M, Moura VEC, Favarini MO, Leal KPG, Wagner PGC, Dos Santos MC, Sanderson J, Araújo EP, Rodrigues FHG. Ecological modeling, biogeography, and phenotypic analyses setting the tiger cats' hyperdimensional niches reveal a new species. Sci Rep 2024; 14:2395. [PMID: 38287072 PMCID: PMC10825201 DOI: 10.1038/s41598-024-52379-8] [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: 08/15/2023] [Accepted: 01/18/2024] [Indexed: 01/31/2024] Open
Abstract
Recently, the tiger-cat species complex was split into Leopardus tigrinus and Leopardus guttulus, along with other proposed schemes. We performed a detailed analysis integrating ecological modeling, biogeography, and phenotype of the four originally recognized subspecies-tigrinus, oncilla, pardinoides, guttulus-and presented a new multidimensional niche depiction of the species. Species distribution models used > 1400 records from museums and photographs, all checked for species accuracy. Morphological data were obtained from institutional/personal archives. Spotting patterns were established by integrating museum and photographic/camera-trap records. Principal component analysis showed three clearly distinct groups, with the Central American specimens (oncilla) clustering entirely within those of the Andes, namely the pardinoides group of the cloud forests of the southern Central-American and Andean mountain chains (clouded tiger-cat); the tigrinus group of the savannas of the Guiana Shield and central/northeastern Brazil (savanna tiger-cat); and the guttulus group in the lowland forests of the Atlantic Forest domain (Atlantic Forest tiger-cat). This scheme is supported by recent genetic analyses. All species displayed different spotting patterns, with some significant differences in body measurements/proportions. The new distribution presented alarming reductions from the historic range of - 50.4% to - 68.2%. This multidimensional approach revealed a new species of the elusive and threatened tiger-cat complex.
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Affiliation(s)
- Tadeu G de Oliveira
- Departamento de Biologia, Universidade Estadual do Maranhão (UEMA), Campus Paulo VI, Av. Lourenço Vieira da Silva 1000, Jardim São Cristóvão, São Luís, Maranhão, 65055-310, Brazil.
- Instituto Pro-Carnívoros, Atibaia, SP, Brazil.
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil.
- Programa de Pós-Graduação em Ecologia, Conservação e Manejo da Vida Silvestre -ECMVS, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.
| | - Lester A Fox-Rosales
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Programa de Pós-Graduação em Ciência Animal, UEMA, São Luís, MA, Brazil
| | - José D Ramírez-Fernández
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Oncilla Conservation, Costa Rica Wildlife Foundation, San José, Costa Rica
| | | | - Rebecca Zug
- Universidad San Francisco de Quito, Quito, Ecuador
| | - Catalina Sanchez-Lalinde
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Onca Fundación para el Estudio de la Diversidad, Bogota, Colombia
| | - Marcelo J R Oliveira
- Programa de Pós-Graduação em Ecologia, Conservação e Manejo da Vida Silvestre -ECMVS, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
- Instituto Biotrópicos, Diamantina, MG, Brazil
| | - Paulo H D Marinho
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Alejandra Bonilla-Sánchez
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Mara C Marques
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Zoológico de São Paulo Zoo, São Paulo, SP, Brazil
| | | | - Ricardo Moreno
- Fundación Yaguará Panamá, Ciudad del Saber/Panama City, Panama
| | - Damián Rumiz
- Noel Kempff Mercado Natural History Museum, Santa Cruz de la Sierra, Bolivia
| | - Felipe B Peters
- Instituto Pro-Carnívoros, Atibaia, SP, Brazil
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Programa de Pós-Graduação em Biologia Animal, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Josué Ortega
- Fundación Yaguará Panamá, Ciudad del Saber/Panama City, Panama
- Smithsonian Tropical Research Institute, Balboa Ancon, Panama
| | | | - Michael S Mooring
- Point Loma Nazarene University, San Diego, CA, USA
- Quetzal Education & Research Center (QERC), San Gerardo de Dota, Costa Rica
| | | | | | - Douglas Dias
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Programa de Pós-Graduação em Ecologia, Conservação e Manejo da Vida Silvestre -ECMVS, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
- SETEG- Soluções Geológicas e Ambientais, Fortaleza, CE, Brazil
| | - Fábio D Mazim
- Instituto Pro-Carnívoros, Atibaia, SP, Brazil
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Ka'aguy Consultoria Ambiental, Pelotas, RS, Brazil
| | - Eduardo Eizirik
- Instituto Pro-Carnívoros, Atibaia, SP, Brazil
- Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Jaime L Diehl
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
| | | | - Ana Carolina C Ribeiro
- Instituto de Ciências Biológicas, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | | | - Emanuelle Pasa
- Cruzeiro do Sul Consultoria Ambiental Ltda., Ivoti, RS, Brazil
| | - Lyse P C Meira
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Bioconsultoria Ambiental Ltda., Caetité, BA, Brazil
| | - Alex Pereira
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Bioconsultoria Ambiental Ltda., Caetité, BA, Brazil
| | | | | | - Liana M M Sena
- Programa de Pós-Graduação em Ecologia, Conservação e Manejo da Vida Silvestre -ECMVS, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | | | - Micheli Ribeiro Luiz
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Instituto Felinos do Aguaí, Siderópolis, SC, Brazil
| | - Vitor E C Moura
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Programa de Pós-Graduação em Ecologia e Conservação da Biodiversidade, UEMA, São Luís, MA, Brazil
| | - Marina O Favarini
- Instituto Pro-Carnívoros, Atibaia, SP, Brazil
- Tiger Cats Conservation Initiative (TCCI), São Luís, Brazil
- Programa de Pós-Graduação em Biologia Animal, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Karla P G Leal
- Universidade Federal de Lavras (UFLA), Lavras, MG, Brazil
| | - Paulo G C Wagner
- Centro de Triagem de Animais Silvestres CETAS, IBAMA-RS, Porto Alegre, RS, Brazil
| | | | - James Sanderson
- Re:wild, Austin, TX, USA
- Small Wild Cat Conservation Foundation, Corrales, NM, USA
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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.
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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
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Kim S, Schwenk J, Walkup D, Zeng Y, Ghahari F, Le ST, Slot MR, Berwanger J, Blankenship SR, Watanabe K, Taniguchi T, Giessibl FJ, Zhitenev NB, Dean CR, Stroscio JA. Edge channels of broken-symmetry quantum Hall states in graphene visualized by atomic force microscopy. Nat Commun 2021; 12:2852. [PMID: 33990565 PMCID: PMC8121811 DOI: 10.1038/s41467-021-22886-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 02/15/2021] [Accepted: 03/30/2021] [Indexed: 11/09/2022] Open
Abstract
The quantum Hall (QH) effect, a topologically non-trivial quantum phase, expanded the concept of topological order in physics bringing into focus the intimate relation between the "bulk" topology and the edge states. The QH effect in graphene is distinguished by its four-fold degenerate zero energy Landau level (zLL), where the symmetry is broken by electron interactions on top of lattice-scale potentials. However, the broken-symmetry edge states have eluded spatial measurements. In this article, we spatially map the quantum Hall broken-symmetry edge states comprising the graphene zLL at integer filling factors of [Formula: see text] across the quantum Hall edge boundary using high-resolution atomic force microscopy (AFM) and show a gapped ground state proceeding from the bulk through to the QH edge boundary. Measurements of the chemical potential resolve the energies of the four-fold degenerate zLL as a function of magnetic field and show the interplay of the moiré superlattice potential of the graphene/boron nitride system and spin/valley symmetry-breaking effects in large magnetic fields.
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Affiliation(s)
- Sungmin Kim
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Johannes Schwenk
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Daniel Walkup
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Yihang Zeng
- Department of Physics, Columbia University, New York, NY, USA
| | - Fereshte Ghahari
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Son T Le
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Theiss Research, La Jolla, CA, USA
| | - Marlou R Slot
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Department of Physics, Georgetown University, Washington, DC, USA
| | - Julian Berwanger
- Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany
| | - Steven R Blankenship
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany
| | - Nikolai B Zhitenev
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Cory R Dean
- Department of Physics, Columbia University, New York, NY, USA.
| | - Joseph A Stroscio
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
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Botts RT, Eppert AA, Wiegman TJ, Rodriguez A, Blankenship SR, Asselin EM, Garley WM, Wagner AP, Ullrich SE, Allen GR, Mooring MS. Circadian activity patterns of mammalian predators and prey in Costa Rica. J Mammal 2020; 101:1313-1331. [PMID: 33343263 PMCID: PMC7733402 DOI: 10.1093/jmammal/gyaa103] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 12/14/2019] [Accepted: 07/28/2020] [Indexed: 11/12/2022] Open
Abstract
Temporal niche shifts can shape predator-prey interactions by enabling predator avoidance, enhancing feeding success, and reducing competition among predators. Using a community-based conservation approach, we investigated temporal niche partitioning of mammalian predators and prey across 12 long-term camera trap surveys in the Pacific slope and Talamanca Cordillera of Costa Rica. Temporal overlap and segregation were investigated between predator-prey and predator-predator pairs using overlap analysis, circular statistics, and relative abundance after accounting for differences in habitat, season, and human impact among sites. We made the assumption that predators select abundant prey and adjust their activity to maximize their temporal overlap, thus we predicted that abundant prey with high overlap would be preferred prey species for that predator. We also predicted that similar-sized pairs of predator species with the greatest potential for competitive interactions would have the highest temporal segregation. Our results supported the existence of temporal niche separation among the eight species of predators-the smaller Leopardus felids (ocelot, margay, oncilla) were primarily nocturnal, the largest felids (jaguar and puma) and coyote were cathemeral, and the smaller jaguarundi and tayra were mostly diurnal. Most prey species (67%) were primarily nocturnal versus diurnal or cathemeral (33%). Hierarchical clustering identified relationships among species with the most similar activity patterns. We discuss the primary prey and competitor species predicted for each of the eight predators. Contrary to our prediction, the activity pattern of similar-sized intraguild competitors overlapped more than dissimilar-sized competitors, suggesting that similar-sized predators are hunting the same prey at the same time. From this we conclude that prey availability is more important than competition in determining circadian activity patterns of Neotropical predators. Our results indicate the presence of a delicate balance of tropical food webs that may be disrupted by overhunting, leading to a depauperate community consisting of ubiquitous generalists and endangered specialists. With Central America a hotspot for hunting-induced "empty forests," community-based conservation approaches may offer the best road to reduce illegal hunting and maintain the biodiversity and community structure of tropical forest systems.
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Affiliation(s)
- Ryan T Botts
- Point Loma Nazarene University, Department of Mathematical, Information and Computer Science, San Diego, CA, USA
| | - Amy A Eppert
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | - Timothy J Wiegman
- Point Loma Nazarene University, Department of Physics and Engineering, San Diego, CA, USA
| | - Abner Rodriguez
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | | | - Ellen M Asselin
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | - Wyatt M Garley
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | - Abigail P Wagner
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | - Sierra E Ullrich
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | - Gabrielle R Allen
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
| | - Michael S Mooring
- Point Loma Nazarene University, Department of Biology, San Diego, CA, USA
- Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica
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Schwenk J, Kim S, Berwanger J, Ghahari F, Walkup D, Slot MR, Le ST, Cullen WG, Blankenship SR, Vranjkovic S, Hug HJ, Kuk Y, Giessibl FJ, Stroscio JA. Achieving μeV tunneling resolution in an in-operando scanning tunneling microscopy, atomic force microscopy, and magnetotransport system for quantum materials research. Rev Sci Instrum 2020; 91:071101. [PMID: 32752869 PMCID: PMC7678032 DOI: 10.1063/5.0005320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
Research in new quantum materials requires multi-mode measurements spanning length scales, correlations of atomic-scale variables with a macroscopic function, and spectroscopic energy resolution obtainable only at millikelvin temperatures, typically in a dilution refrigerator. In this article, we describe a multi-mode instrument achieving a μeV tunneling resolution with in-operando measurement capabilities of scanning tunneling microscopy, atomic force microscopy, and magnetotransport inside a dilution refrigerator operating at 10 mK. We describe the system in detail including a new scanning probe microscope module design and sample and tip transport systems, along with wiring, radio-frequency filtering, and electronics. Extensive benchmarking measurements were performed using superconductor-insulator-superconductor tunnel junctions, with Josephson tunneling as a noise metering detector. After extensive testing and optimization, we have achieved less than 8 μeV instrument resolving capability for tunneling spectroscopy, which is 5-10 times better than previous instrument reports and comparable to the quantum and thermal limits set by the operating temperature at 10 mK.
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Affiliation(s)
- Johannes Schwenk
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA
| | - Sungmin Kim
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA
| | - Julian Berwanger
- Institute of Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Fereshte Ghahari
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA
| | - Daniel Walkup
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA
| | - Marlou R. Slot
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Physics, Georgetown University, Washington, DC 20007, USA
| | - Son T. Le
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Theiss Research, La Jolla, CA 92037, USA
| | - William G. Cullen
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Steven R. Blankenship
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Sasa Vranjkovic
- Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Hans J. Hug
- Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Young Kuk
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Franz J. Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Joseph A. Stroscio
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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Song YJ, Otte AF, Shvarts V, Zhao Z, Kuk Y, Blankenship SR, Band A, Hess FM, Stroscio JA. Invited review article: A 10 mK scanning probe microscopy facility. Rev Sci Instrum 2010; 81:121101. [PMID: 21198007 DOI: 10.1063/1.3520482] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We describe the design, development and performance of a scanning probe microscopy (SPM) facility operating at a base temperature of 10 mK in magnetic fields up to 15 T. The microscope is cooled by a custom designed, fully ultra-high vacuum (UHV) compatible dilution refrigerator (DR) and is capable of in situ tip and sample exchange. Subpicometer stability at the tip-sample junction is achieved through three independent vibration isolation stages and careful design of the dilution refrigerator. The system can be connected to, or disconnected from, a network of interconnected auxiliary UHV chambers, which include growth chambers for metal and semiconductor samples, a field-ion microscope for tip characterization, and a fully independent additional quick access low temperature scanning tunneling microscope (STM) and atomic force microscope (AFM) system. To characterize the system, we present the cooling performance of the DR, vibrational, tunneling current, and tip-sample displacement noise measurements. In addition, we show the spectral resolution capabilities with tunneling spectroscopy results obtained on an epitaxial graphene sample resolving the quantum Landau levels in a magnetic field, including the sublevels corresponding to the lifting of the electron spin and valley degeneracies.
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Affiliation(s)
- Young Jae Song
- Center for Nanoscale Science and Technology, NIST, Gaithersburg, Maryland 20899, USA
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