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So far Lauren Mason has created 237 blog entries.

Predicting heat flow in 3D semiconductor nanosystems

Nanostructuring on length scales corresponding to phonon mean free paths provides control over heat flow in semiconductors and makes it possible, in principle, to engineer their thermal properties. However, this is currently not feasible because there is no general description for heat flow in 3D nanostructured semiconductors. In recent research, STROBE scientists used short wavelength extreme ultraviolet beams to study heat transport in a silicon metalattice with deep nanoscale features. They observed dramatically reduced thermal conductivity relative to bulk—about x50 times less than current model predictions. To explain this, they developed a new predictive theory that incorporates the idea that heat-carrying lattice vibrations can behave like a fluid—spreading out instead of just moving ballistically in straight lines. Moreover, this new theory of heat transport can be used to predict and engineer phonon transport in many other 3D nanosystems including nanowires and nanomeshes, that are of great interest for next-generation energy-efficient devices.

How 1,000 undergraduates helped solve an enduring mystery about the sun

For a new study, a team of physicists recruited roughly 1,000 undergraduate students at CU Boulder to help answer one of the most enduring questions about the sun: How does the star’s outermost atmosphere, or “corona,” get so hot? The research represents a nearly-unprecedented feat of data analysis: From 2020 to 2022, the small army of mostly first- and second-year students examined the physics of more than 600 real solar flares—gigantic eruptions of energy from the sun’s roiling corona…

Introduction to Electron Microscopy for Materials Science

Abstract: This talk will introduce the basics of Transmission Electron Microscopy (TEM)  imaging, spectroscopy and diffraction techniques to a general audience and show recent highlights of new techniques for materials characterization. Modern TEMs combine atomic-level imaging and spectroscopy with quantitative diffraction analysis, providing a powerful toolkit for probing the structure and chemistry of materials. Recent technological advances in instrumentation such as stages and direct electron detectors have enabled new capabilities and modes of imaging.  This talk will also highlight selected in situ observations of the dynamic physical behavior of materials in response to external stimuli such as temperature, environment, stress, and applied fields.

Bio: Andrew Murphy Minor is a Professor at the University of California, Berkeley in the Department of Materials Science and Engineering and also holds a joint appointment at the Lawrence Berkeley National Laboratory where he is the Facility Director of the National Center for Electron Microscopy in the Molecular Foundry. He has over 260 publications in the fields of nanomechanics, metallurgy, electron characterization of soft matter and in situ transmission electron microscopy technique development. Minor’s honors include the LBL Materials Science Division Outstanding Performance Award (2006 & 2010), the AIME Robert Lansing Hardy Award from TMS (2012) and the Burton Medal from the Microscopy Society of America (2015). Currently, he is the President of the Microscopy Society of America.

Label-free measurement of nanoscale energy flow using time-resolved scattering microscopy

Abstract: From photo-generated heat and charge carriers in metals and semiconductors to excited chlorophyll molecules in plants’ photosynthetic membranes, understanding how energy flows through and is dissipated by systems with nanoscale heterogeneity is of great interest for emerging energy technologies, including photovoltaics, transistors, and artificial photosynthesis. The dynamics of charge carrier migration following photoexcitation take place over sub-picosecond to nanosecond timescales and nanometer length scales. Imaging such a wide variety of energy carriers in such varied materials calls for a microscopy modality with high temporal resolution and spatial sensitivity without the need for labeling. Time-resolved interferometric scattering microscopy (stroboSCAT), developed in the Ginsberg Lab, ticks many of these boxes, relying on interference between light scattered by a sample and light reflected by the substrate to achieve high sensitivity at low fluences. In stroboSCAT, a pump-probe technique, a diffraction-limited volume is excited by a focused optical pump and imaged some time later by a widefield probe pulse. The technique allows direct imaging of excitons, heat, and any other energy carriers that alter the local polarizability and thus the scattering cross-section of the sample. Using this technique, the Ginsberg Group has studied exciton migration in hybrid organic-inorganic perovskites and organic semiconductors, charge and heat migration in silicon and 2D transition metal dichalcogenides, and subdiffusive heat transfer in gold nanocrystal films, and more, revealing insights into the role of nanoscale heterogeneity on energy transfer.
 
Bio: Leo Hamerlynck is a fifth-year graduate student in Prof. Naomi Ginsberg’s lab at UC Berkeley. At Berkeley, Leo has studied energy transfer in proteins involved in photosynthesis through time-resolved spectroscopy and microscopy in order to understand what gives rise to its excellent energy transfer efficiency. Leo has used ultrafast transient absorption anisotropy measurements to understand the impacts of different types of disorder on intra-protein energy transfer in a model light-harvesting complex based on TMV. Leo’s recent work focuses on applying stroboSCAT to intact thylakoid membranes to investigate inter-protein energy transfer in photosynthesis.

Congrats to Emma Nelson for Receiving an NSF Graduate Research Fellowship

The NSF GRFP recognizes and supports outstanding graduate students in NSF-supported STEM disciplines who are pursuing research-based master’s and doctoral degrees at accredited US institutions. The purpose of the NSF Graduate Research Fellowship Program (GRFP) is to ensure the quality, vitality, and diversity of the scientific and engineering workforce of the United States. GRFP seeks to broaden participation in science and engineering of underrepresented groups, including women, minorities, persons with disabilities, and veterans. The five-year fellowship provides three years of financial support inclusive of an annual stipend of $37,000.

Imaging Topological Magnetic Monopoles in 3D

Researchers created topologically stable magnetic monopoles and imaged them in 3D with unprecedented spatial resolution using a technique developed at the Advanced Light Source (ALS). The work enables the study of magnetic monopole behavior for both fundamental interest and potential use in information storage and transport applications. A bar magnet cut in half will always have a north and south pole, ad infinitum. Thus, magnetic monopoles—particles with a single magnetic “charge”—have never been observed in isolation. Yet the idea continues to intrigue: How would magnetic monopoles behave? What could you do with the magnetic equivalent of electric charge or current? Remarkably, scientists might be able to explore such questions via quasiparticles—particle-like phenomena emerging from collective interactions in condensed matter. However, it has been difficult to directly measure these quasiparticles and probe their behavior at the nanoscale…

Postdoctoral Research Associate for Electron Microscopy Study of Quantum Materials

The Advanced Electron Microscopy and Nanostructured Materials Group in CMPMS, BNL, is seeking postdoctoral research associate for electron microscopy study of quantum materials.

The goal of the research is to explore, understand, and control the novel physical mechanisms of quantum materials, including charge-spin-lattice correlations at a wide range of temperatures, especially at low temperatures where intriguing materials behavior emerges. The research will focus on quantum materials that exhibit intriguing physical behavior such as insulator-metal-transition, interface/defects induced charge-spin interactions, or topological properties for novel forms of information storage and manipulation.

The position will provide an exceptional opportunity for research in quantum materials and devices for one or two of the following areas: strongly correlated electron systems, multiferroics, topological materials, skyrmions, and 2-D transition metal dichalcogenides, at the forefront of electron microscopy with extraordinary spatiotemporal resolutions to understand structure-property relationship. Planned experiments with quantitative data analyses include, but not limited to, low temperature atomic imaging, high energy-resolution energy-loss spectroscopy, nanoprobe 4D scanning diffraction, and in-situ electromagnetic biasing and microwave excitation.  The work will be conducted under the direction of Dr. Yimei Zhu. Close collaborations with leading theoretical and experimental groups at BNL and elsewhere are an essential ingredient of the research.

 

Position Requirements:

o Ph.D. in Condensed Matter Physics, Materials Science, or closely related fields.

o Solid background in electron microscopy and structural characterization.

o Experience in aberration corrected electron microscopy and/or monochromated electron energy-loss-spectroscopy.

o Effective communication skills.

BNL policy states that research associate appointments may be made to individuals who have received their Ph.D. within the past five years. BNL is an Affirmative Action/Equal Opportunity Employer committed to the development of a diverse workforce.

For those interested and qualified please contact Professor Yimei Zhu at zhu@bnl.gov.

Femtosecond Electric-Field Induced Manipulation of Coherent Magnetic Excitation

Abstract: The wildly growing field of antiferromagnetic spintronics is currently addressing several fundamental questions. A major topic of investigation concerns the generation and manipulation of coherent magnons on the ultrafast timescale. The development of novel pulsed-laser sources has enabled scientists to address the following scientific question: which magnetic excited state can be induced by resonantly driving coherent magnons throughout the Brillouin zone? In my talk, I will outline our approach to this open issue, which relies on the resonant drive of pairs of high-energy magnons in the weak ferromagnet α-Fe2O3 (hematite), with wavevector near the edges of the Brillouin zone. This unprecedented concept results in a strong perturbation of the entire magnetic system of the material, in particular: i) magnon modes with different wavevectors are excited and amplified; ii) the eigenfrequencies of magnons are modified, which demonstrates a modification of the magnon dispersion; iii) a coupling between magnon modes that are orthogonal eigenstates of the magnetic Hamiltonian of the material is observed. Additionally, the effect of light on the magnetic system is quantified by quantitatively estimating the modification of the magnetic interactions. All these observations are rationalised in view of a resonant impulsive stimulated Raman scattering mechanism. Our results offer perspectives to establish an all-optical arbitrary tailoring of the spectrum of the magnetic excitations of a given material on the fundamental timescales. 

Research Scientist, X-ray Microscopy (STXM)

Lawrence Berkeley National Lab’s (LBNL) Advanced Light Source Division (ALS) has an opening available for a scientist to work on the development and application of coherent soft x-ray microscopy to problems in physics, materials, energy and environmental science.

 

The ALS is a U.S. Department of Energy (DOE) Office of Science national scientific user facility whose excellent scientific reputation, expert staff, and capabilities in the soft x-ray, hard x-ray, and infrared regimes attract more than 1,800 academic and industrial users each year in disciplines spanning physical, chemical, materials, biological, energy, and Earth sciences. It is one of five Berkeley Lab user facilities that serve a combined 14,000 users annually. The ALS has been a global leader in soft x-ray science for more than two decades and is currently undergoing a large-scale upgrade (ALS-U) that will endow the facility with revolutionary x-ray capabilities. It’s an exciting time to join our team!

 

In this exciting role, as part of the ALS Microscopy Program, you will take charge of the scanning transmission and ptychography microscope (the endstation at beamline 7.0.1.2, COSMIC Imaging) to support and collaborate with the community of external scientists using the ALS. You will work in a multidisciplinary scientific research environment, collaborating with a variety of colleagues at all levels for day-to-day operations as well as research and instrumentation projects. The ALS offers fantastic opportunities to develop your own research program using state-of-the-art instrumentation in a vibrant scientific environment.

 

What You Will Do:

  • Establish day-to-day operations of the scanning x-ray microscopy endstation at ALS beamline 7.0.1.2 and support other scientists in their safe use of this instrument
  • Maintain, upgrade and develop instrumentation and software for x-ray microscopy as required to support ALS users and to meet emerging needs of the user community
  • Collaborate with existing ALS users and develop new partnerships for performing state of the art x-ray experiments. Develop a professional network and a research program that align with the strategic goals of the ALS.
  • Document and communicate your work, including publishing results in peer-reviewed scientific and technical journals, and presenting findings at workshops and conferences
  • Communicate with ALS Users to plan and prepare for upcoming experiments
  • Review and analyze experimental data using commercial and custom software. Maintain and develop custom beamline software in collaboration with the Microscopy program and your own network.
  • Coordinate activities with subject matter experts and technicians, such as safety, mechanical, electrical, vacuum, experiment controls, etc.
  • Serve the broader scientific community as an expert resource for advisory/organizational committees, journals, and scientists at other institutions
  • Practice Integrated Safety Management (ISM) in all aspects of your work.
  • Embrace and practice concepts of Inclusion, Diversity, Equity, and Accountability (IDEA) and Stewardship

 

What is Required:

  • Ph.D. in the physical sciences, chemical sciences, or engineering or equivalent experience, as demonstrated by broad knowledge of and experience in synchrotron radiation science and instrumentation.
  • Demonstrated scientific publication record.
  • Practical knowledge of physics or materials science and their applications in scientific research.
  • Understanding of coherent soft x-ray techniques; demonstrated experience in the operation of complex research equipment.
  • Advanced experience in programming for data analysis and instrument controls.
  • Ability to teach effective and safe operation of scientific instruments.
  • Ability to work with and maintain effective professional relationships with scientific staff, technical staff, and with people from diverse backgrounds.
  • Ability to manage competing priorities, and provide quality work on schedule.
  • Excellent organizational and problem-solving skills.
  • Well developed analytical and quantitative skills.
  • Strong technical and scientific communication skills, both oral and written.
  • Flexibility to perform other duties as assigned/needed.

 

Desired Qualifications:

  • Experience with coherent x-ray spectromicroscopy, and its applications in materials or energy science, magnetism, biomineralization, environmental science or microelectronics.
  • Experience in other experimental techniques used in a relevant research area, such as coherent x-ray scattering, electrochemistry, microfluidics, thin film sample preparation or microwave excitation.
  • Experience in developing and troubleshooting experimental instrumentation, with emphasis on nano-motion controls, high vacuum systems, and x-ray detectors.
  • Two or more years of experience working with x-ray beamlines and endstations.
  • Ability to lead and drive projects in an interactive team setting.
  • Ability to write and maintain Python software packages.

 

Want to learn more about Berkeley Lab’s Culture, Benefits and answers to FAQs? Please visit: https://recruiting.lbl.gov/

 

For full consideration, please apply by April 15, 2023.

 

Notes:

  • This is a full time, 2 years, career-track term appointment that may be renewed to a maximum of five years and that may be converted to career based upon satisfactory job performance, continuing availability of funds, and ongoing operational needs.
  • This position is expected to pay $7,256.00 – $11,610.00/month, which fits within the full salary range of  $7,256.00 –  $17,415.00/month for the S13.1 – Physicist Research Sci/Engr. Salary for this position will be commensurate with the final candidate’s qualification and experience, including skills, knowledge, relevant education, certifications, plus also aligned with the internal peer group.
  • This position may be subject to a background check. Any convictions will be evaluated to determine if they directly relate to the responsibilities and requirements of the position. Having a conviction history will not automatically disqualify an applicant from being considered for employment.
  • Work will be primarily performed at Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA.

 

The core values of the ALS reflect a strong commitment to diversity, equity, and inclusion. We seek candidates who will support a culture in which each member of the community feels welcomed and valued. An ongoing commitment to recruiting and retaining a vibrant, diverse, and talented workforce is paramount to promoting a strong and successful lab community. For more information refer to the LBNL core values and the ALS mission statement and core values.

 

Based on University of California Policy – SARS-CoV-2 (COVID-19) Vaccination Program and U.S Federal Government requirements, Berkeley Lab requires that all members of our community obtain the COVID-19 vaccine as soon as they are eligible. As a condition of employment at Berkeley Lab, all Covered Individuals must Participate in the COVID-19 Vaccination Program by providing proof that vaccination requirements have been met or submitting a request for Exception or Deferral. Visit covid.lbl.gov for more information.

 

Berkeley Lab is committed to Inclusion, Diversity, Equity and Accountability (IDEA) and strives to continue building community with these shared values and commitments. Berkeley Lab is an Equal Opportunity and Affirmative Action Employer. We heartily welcome applications from women, minorities, veterans, and all who would contribute to the Lab’s mission of leading scientific discovery, inclusion, and professionalism. In support of our diverse global community, all qualified applicants will be considered for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, age, or protected veteran status.

 

Equal Opportunity and IDEA Information Links:

Know your rights, click here for the supplement: Equal Employment Opportunity is the Law and the Pay Transparency Nondiscrimination Provision under 41 CFR 60-1.4.

Congratulations to Yuka Esashi for Being Awarded the 2023 SPIE Karel Urbánek Best Student Paper Award

At the 2023 Advanced Lithography and Patterning Conference, Yuka Esashi was awarded the SPIE Karel Urbánek Best Student Paper Award for “Multi-modal tabletop EUV reflectometry for characterization of nanostructures.” Congratulations, Yuka!

The Karel Urbánek Best Student Paper Award recognizes the most promising contribution to the field by a student, based on the technical merit and persuasiveness of the paper presentation at the conference. The Karel Urbánek Best Student Paper Award consists of an SPIE citation and an honorarium. To be eligible, the leading author and presenter of the paper must be a student.

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