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Exploring the magnetic properties of individual barcode nanowires using wide-field diamond microscopy

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arXiv 2023年

作者： Yoon, Jungbae Moon, Jun Hwan Jeong, Jugyeong Kim, Yu Jin Kim, Kihwan Kang, Hee Seong Jeon, Yoo Sang Oh, Eunsoo Lee, Sun Hwa Han, Kihoon Lee, Dongmin Lee, Chul-Ho Kim, Young Keun Lee, Donghun Department of Physics Korea University Seoul Korea Republic of Department of Materials Science and Engineering Korea University Seoul Korea Republic of Institute for High Technology Materials and Devices Korea University Seoul Korea Republic of KU-KIST Graduate School of Converging Science and Technology Korea University Seoul Korea Republic of Center for Hydrogen∙Fuel Cell Research Korea Institute of Science and Technology Seoul Korea Republic of Ulsan44919 Korea Republic of BK21 Graduate Program Department of Biomedical Sciences Korea University College of Medicine Seoul Korea Republic of Department of Neuroscience Korea University College of Medicine Seoul Korea Republic of Department of Anatomy Korea University College of Medicine Seoul Korea Republic of

Barcode magnetic nanowires typically comprise a multilayer magnetic structure in a single body with more than one segment type. Interestingly, owing to selective functionalization and novel interactions between the layers, barcode magnetic nanowires have attracted significant attention, particularly in the field of bioengineering. However, an analysis of their magnetic properties at the individual nanowire level remains challenging. With this background, herein, we investigated the characterization of magnetic nanowires at room temperature under ambient conditions based on magnetic images obtained via wide-field quantum microscopy with nitrogen-vacancy centers in diamond. Consequently, we could extract critical magnetic properties, such as the saturation magnetization and coercivity, of single nanowires by comparing the experimental results with those of micromagnetic simulations. This study opens up the possibility for a versatile characterization method suited to individual magnetic nanowires. © 2023, CC BY.

关键词： Diamonds

Dispersion Engineered Metasurfaces for Broadband, High-NA, High-Efficiency, Dual-Polarization Analog Image Processing

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arXiv 2022年

作者： Cotrufo, Michele Arora, Akshaj Singh, Sahitya Alù, Andrea Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States The Institute of Optics University of Rochester RochesterNY14627 United States Physics Program Graduate Center of the City University of New York New YorkNY10016 United States

Optical metasurfaces performing analog image processing – such as spatial differentiation and edge detection – hold the potential to reduce processing times and power consumption, while avoiding bulky 4F lens systems. However, current designs have been suffering from trade-offs between spatial resolution, throughput, polarization asymmetry, operational bandwidth, and isotropy. Here, we show that dispersion engineering provides an elegant way to design metasurfaces where all these critical metrics are simultaneously optimized. We experimentally demonstrate silicon metasurfaces performing isotropic and dual-polarization edge detection, with numerical apertures above 0.35 and spectral bandwidths of 35 nm around 1500 nm. Moreover, we introduce quantitative metrics to assess the efficiency of these devices. Thanks to the low loss nature and dual-polarization response, our metasurfaces feature large throughput efficiencies, approaching the theoretical maximum for a given NA. Our results pave the way for low-loss, high-efficiency and broadband optical computing and image processing with free-space metasurfaces. © 2022, CC BY.

关键词： Optical data processing

Enhancement of Self-Trapped Exciton and Near-Infrared Emission in Bi3+/Er3+ Co-Doped Cs2Ag0.4Na0.6InCl6 Double Perovskite for Optical Telecommunications

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SSRN

SSRN 2022年

作者： Dave, Kashyap Huang, Wen-Tse Leśniewski, Tadeusz Lazarowska, Agata Grzegorczyk, Maciej Mahlik, Sebastian Leniec, Grzegorz Kaczmarek, Slawomir M. Liu, Ru-Shi Department of Chemistry National Taiwan University Taipei106 Taiwan Nanoscience and Technology Program Taiwan International Graduate Program Academia Sinica National Taiwan University Taipei115 Taiwan Institute of Experimental Physics Faculty of Mathematics Physics and Informatics University of Gdańsk Gdańsk80-308 Poland Department of Technical Physics Faculty of Mechanical Engineering and Mechatronics West Pomeranian University of Technology in Szczecin Piastow 48 Szczecin70-311 Poland Advanced Research Center of Green Materials Science and Technology National Taiwan University Taipei106 Taiwan

Erbium (Er) complexes are used as optical gain material for signal generation in the telecom C-band at 1540 nm, but they need a sensitizer to enhance absorption. Na+ substitution at Ag+ and Bi3+ doping at the In3+ site are possible strategies to enhance broadband emission in Cs2AgInCl6, which could be used as sensitizers to energy transfer into rare-earth elements. Herein, self-trapped exciton (STE) energy transfer to Er3+ at 1540 nm for low loss optical telecommunication applications is reported. An acid precipitation method is used to synthesize Cs2AgInCl6 and its derivative with Er3+, Bi3+, and Na+. Bare Cs2AgInCl6:Er emission signals are found to be weak at 1540 nm, but Bi3+ doping increased by 12 times, and Bi3+ and Na+ doping increased by up to 25 times signal intensity. Electron paramagnetic resonance spectroscopy characterized a decrease in axial symmetry over the Er3+ ion after substitutions of Na+ and Bi3+ in Cs2AgInCl6 at low temperature ( © 2022, The Authors. All rights reserved.

关键词： Bismuth compounds

Enhanced Superconducting Qubit Performance Through Ammonium Fluoride Etch

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arXiv 2024年

作者： Kopas, Cameron J. Goronzy, Dominic P. Pham, Thang Torres Castanedo, Carlos G. Cheng, Matthew Cochrane, Rory Nast, Patrick Lachman, Ella Zhelev, Nikolay Z. Vallières, André Murthy, Akshay A. Oh, Jin-Su Zhou, Lin Kramer, Matthew J. Cansizoglu, Hilal Bedzyk, Michael J. Dravid, Vinayak P. Romanenko, Alexander Grassellino, Anna Mutus, Josh Y. Hersam, Mark C. Yadavalli, Kameshwar Rigetti Computing BerkeleyCA United States Department of Materials Science and Engineering Northwestern University EvanstonIL United States Center for Applied Physics and Superconducting Technologies Northwestern University EvanstonIL United States Department of Physics and Astronomy Northwestern University EvanstonIL United States Department of Physics University of Oregon EugeneOR United States Graduate Program in Applied Physics Northwestern University EvanstonIL60208 United States Fermi National Accelerator Laboratory BataviaIL United States Ames Laboratory U.S. Department of Energy AmesIA United States Northwestern University EvanstonIL United States Department of Chemistry Northwestern University EvanstonIL United States Department of Electrical and Computer Engineering Northwestern University EvanstonIL United States

The performance of superconducting qubits is often limited by dissipation and two-level systems (TLS) losses. The dominant sources of these losses are believed to originate from amorphous materials and defects at interfaces and surfaces, likely as a result of fabrication processes or ambient exposure. Here, we explore a novel wet chemical surface treatment at the Josephson junction-substrate and the substrate-air interfaces by replacing a buffered oxide etch (BOE) cleaning process with one that uses hydrofluoric acid followed by aqueous ammonium fluoride. We show that the ammonium fluoride etch process results in a statistically significant improvement in median T1 by ∼ 22% (p = 0.002), and a reduction in the number of strongly-coupled TLS in the tunable frequency range. Microwave resonator measurements on samples treated with the ammonium fluoride etch prior to niobium deposition also show ∼ 33% lower TLS-induced loss tangent compared to the BOE treated samples. As the chemical treatment primarily modifies the Josephson junction-substrate interface and substrate-air interface, we perform targeted chemical and structural characterizations to examine materials’ differences at these interfaces and identify multiple microscopic changes that could contribute to decreased TLS. © 2024, CC BY-NC-ND.

关键词： Fluorine compounds

Fabry-perot interferometric calibration of 2D nanomechanical plate resonators

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arXiv 2021年

作者： Aguila, Myrron Albert Callera Esmenda, Joshoua Condicion Wang, Jyh-Yang Lee, Teik-Hui Yang, Chi-Yuan Lin, Kung-Hsuan Chang-Liao, Kuei-Shu Kafanov, Sergey Pashkin, Yuri A. Chen, Chii-Dong Department of Engineering and System Science National Tsing Hua University Hsinchu30013 Taiwan Nano Science and Technology Program Taiwan International Graduate Program National Tsing Hua University Academia Sinica Taiwan Institute of Physics Academia Sinica Nankang Taipei11529 Taiwan Department of Physics Lancaster University LancasterLA1 4YB United Kingdom

Displacement calibration of nanomechanical plate resonators presents a challenging task. Large nanomechanical resonator thickness reduces the amplitude of the resonator motion due to its increased spring constant and mass, and its unique reflectance. Here, we show that the plate thickness, resonator gap height, and motional amplitude of circular and elliptical drum resonators, can be determined in-situ by exploiting the fundamental interference phenomenon in Fabry-Perot cavities. The proposed calibration scheme uses optical contrasts to uncover thickness and spacer height profiles, and reuse the results to convert the photodetector signal to the displacement of drumheads that are electromotively driven in their linear regime. Calibrated frequency response and spatial mode maps enable extraction of the modal radius, effective mass, effective driving force and Young’s elastic modulus of the drumhead material. This scheme is applicable to any configuration of Fabry-Perot cavities, including plate and membrane resonators. © 2021, CC BY.

关键词： Fabry-Perot interferometers

Loss tangent fluctuations due to two-level systems in superconducting microwave resonators

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arXiv 2024年

作者： Vallières, André Russell, Megan E. You, Xinyuan Garcia-Wetten, David A. Goronzy, Dominic P. Walker, Mitchell J. Bedzyk, Michael J. Hersam, Mark C. Romanenko, Alexander Lu, Yao Grassellino, Anna Koch, Jens McRae, Corey Rae H. Graduate Program in Applied Physics Northwestern University EvanstonIL60208 United States Fermi National Accelerator Laboratory BataviaIL60510 United States Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States Department of Chemistry Northwestern University EvanstonIL60208 United States Department of Electrical and Computer Engineering Northwestern University EvanstonIL60208 United States Center for Applied Physics and Superconducting Technologies Northwestern University EvanstonIL60208 United States Electrical Computing and Energy Engineering Department University of Colorado BoulderCO80309 United States Department of Physics University of Colorado BoulderCO80309 United States National Institute of Standards and Technology BoulderCO80305 United States

Superconducting microwave resonators are critical to quantum computing and sensing technologies. Additionally, they are common proxies for superconducting qubits when determining the effects of performance-limiting loss mechanisms such as from two-level systems (TLS). The extraction of these loss mechanisms is often performed by measuring the internal quality factor Qi as a function of power or temperature. In this work, we investigate large temporal fluctuations of Qi at low powers over periods of 12 to 16 hours (relative standard deviation σQi/Qi = 13%). These fluctuations are ubiquitous across multiple resonators, chips and cooldowns. We are able to attribute these fluctuations to variations in the TLS loss tangent due to two main indicators. First, measured fluctuations decrease as power and temperature increase. Second, for interleaved measurements, we observe correlations between low- and medium-power Qi fluctuations and an absence of correlations with high-power fluctuations. Agreement with the TLS loss tangent mean is obtained by performing measurements over a time span of a few hours. We hypothesize that, in addition to decoherence due to coupling to individual near-resonant TLS, superconducting qubits are affected by these observed TLS loss tangent fluctuations. © 2024, CC BY.

关键词： Qubits

Transferable screened range-separated hybrid functionals for electronic and optical properties of van der Waals materials

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arXiv 2023年

作者： Camarasa-Gómez, María Ramasubramaniam, Ashwin Neaton, Jeffrey B. Kronik, Leeor Department of Molecular Chemistry and Materials Science Weizmann Institute of Science Rehovoth7610001 Israel Department of Mechanical and Industrial Engineering University of Massachusetts Amherst AmherstMA01003 United States Materials Science and Engineering Graduate Program University of Massachusetts Amherst AmherstMA01003 United States Department of Physics University of California BerkeleyCA94720 United States Materials Sciences Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Kavli Energy NanoSciences Institute at Berkeley University of California BerkeleyCA94720 United States

The accurate description of electronic properties and optical absorption spectra is a long-standing challenge for density functional theory. Recently, the introduction of screened range-separated hybrid (SRSH) functionals for solid-state materials has allowed for the calculation of fundamental band gaps and optical absorption spectra that are in very good agreement with many-body perturbation theory. However, since solid-state SRSH functionals are typically tuned to reproduce the properties of bulk phases, their transferability to low-dimensional structures, which experience substantially different screening than in the bulk, remains an open question. In this work, we explore the transferability of SRSH functionals to several prototypical van der Waals materials, including transition-metal sulfides and selenides, indium selenide, black phosphorus, and hexagonal boron nitride. Considering the bulk and a monolayer of these materials as limiting cases, we show that the parameters of the SRSH functional can be determined systematically, using only the band-edge quasiparticle energies of these extremal structural phases as fitting targets. The resulting SRSH functionals can describe both electronic bandstructures and optical absorption spectra with accuracy comparable to more demanding ab initio many-body perturbation theory (GW and Bethe-Salpeter equation) approaches. Selected examples also demonstrate that the SRSH parameters, obtained from the bulk and monolayer reference structures, display good accuracy for bandstructures and optical spectra of bilayers, indicating a degree of transferability that is independent of the fitting procedure. Copyright © 2023, The Authors. All rights reserved.

关键词： Transition metals

Deep-Strong Coupling between Cavity Photons and Terahertz TO Phonons in PbTe

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Deep-Strong Coupling between Cavity Photons and Terahertz TO...

Conference on Lasers and Electro-Optics (CLEO)

作者： Andrey Baydin Manukumara Manjappa Sobhan Subhra Mishra Hongjing Xu Fuyang Tay Dasom Kim Felix G. G. Hernandez Paulo H. O. Rappl Eduardo Abramof Ranjan Singh Junichiro Kono Department of Electrical and Computer Engineering Rice University Houston Texas USA Smalley-Curl Institute Rice University Houston Texas USA Instrumentation and Applied Physics Department Indian Institute of Science Bangalore India Center for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University Singapore Department of Physics and Astronomy Rice University Houston Texas USA Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston Texas USA Instituto de Física Universidade de São Paulo São Paulo SP Brazil Laboratório Associado de Sensores e Materiais Instituto Nacional de Pesquisas Espaciais São José dos Campos SP Brazil Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore Department of Material Science and NanoEngineering Rice University Houston Texas USA

We have investigated the resonant coupling of photons with TO phonons in lead telluride in small-mode-volume terahertz cavities, observing a giant vacuum Rabi splitting on the order of the bare cavity–phonon frequency.

ISBN: (纸本)9781957171258

关键词： Electric fields Numerical simulation Optical constants Photons Physical vapor deposition Terahertz spectroscopy

Terahertz Cavity Phonon Polaritons in the Deep-Strong Coupling Regime

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Terahertz Cavity Phonon Polaritons in the Deep-Strong Coupli...

International Conference on Infrared and Millimeter Waves

作者： Andrey Baydin Manukumara Manjappa Sobhan Subhra Mishra Hongjing Xu Jacques Doumani Fuyang Tay Dasom Kim Felix G. G. Hernandez Paulo H. O. Rappl Eduardo Abramof Ranjan Singh Junichiro Kono Department of Electrical and Computer Engineering Rice University Houston TX USA Smalley-Curl Institute Rice University Houston TX USA Department of Instrumentation and Applied Physics Indian Institute of Science Bangalore India Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore Department of Physics and Astronomy Rice University Houston TX USA Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston TX USA Instituto de Física Universidade de São Paulo São Paulo SP Brazil Laboratório Associado de Sensores e Materiais Instituto Nacional de Pesquisas Espaciais São José dos ampos SP Brazil Center for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University Singapore Department of Material Science and NanoEngineering Rice University Houston TX USA

We have studied the resonant and nonperturbative coupling of transverse optical phonons in lead telluride with photons in small-mode-volume terahertz cavities, observing a giant vacuum Rabi splitting on the order of the uncoupled phonon and cavity frequencies. Our terahertz time-domain spectroscopy experimental data, systematically collected as a function of sample thickness, temperature, and cavity length, can be well reproduced by our electromagnetic simulations. These results demonstrate that this uniquely tunable platform is promising for realizing and understanding predicted cavity-vacuum-induced ferroelectric instabilities, as well as for exploring applications of light-matter coupling in the ultra-and deep-strong coupling regimes in quantum technology.

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