2014 — 2017 |
Burch, Kenneth |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
High Temperature, Topological Superconductivity Via the Proximity Effect
Non-Technical Abstract This award from the Condensed Matter Physics program of the Division of Materials Research supports Boston University with a project to explore new approach to induce superconductivity in a material using a recently developed proximity technique. Superconductivity, a state of matter in which electrons carry electricity without friction, occurs when a material is cooled below a certain critical temperature. Superconducting states, with relatively "high" transition temperatures (just above that of liquid nitrogen), can be induced by changing the chemistry of a series of magnetic materials. However, this involves changing multiple parameters simultaneously, complicating the analysis. This project follows an alternative approach which is to induce superconductivity via "proximity", namely placing a superconductor in excellent contact with a non-superconducting (normal) material, where the interface and normal state properties can be tuned. The project explores the various aspects of the normal materials that control the emergence of the proximity induced superconducting state. This will enable systematic studies and provide a platform for pursuing the elusive Majorana fermions. To achieve this students of all levels, high school to postdoctoral trainees, will learn a variety of technical (device fabrication and characterization) to professional skills (training, project management).
Technical Abstract This project is to generate new states of matter, while pushing the boundaries of our knowledge on the coupling of order parameters and topology. This will be achieved using a new mechanical bonding technique developed by the principal investigator, which opens the door to creating and manipulating unconventional superconductivity in semiconductors, semimetals and topological insulators. These new platforms will be explored using a combination of optical and transport techniques to address fundamental questions and technical challenges such as: What are the optimum conditions for observing a high Tc superconducting proximity effect? How do band structure, carrier density and topology affect the emergence of superconductivity? How is the symmetry of the superconducting order parameter affected by the host material? Particular focus will be given to the high temperature superconductor Bi2Sr2CaCu2O(8+y) in combination with MoS2, Bi2Te2Se, and Graphite/Graphene. Trainees at all levels will be involved in the fabrication of devices and the analysis of optical/differential conductance data, to learn a variety of analysis, device fabrication and characterization techniques, as well as professional skills.
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0.915 |
2016 — 2019 |
Burch, Kenneth Lowery, Laura Anne (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Reu Site: Integrated Science For Society (Is2)
This REU Site award to Boston College, located in Boston, MA, will support the training of 10 students for 10 weeks during the summers of 2017 - 2019. This project is supported by the Divisions of Biological Infrastructure (DBI) and Chemistry (CHE). Projects will generally pair students from different disciplines to collaborate on solving fundamental science problems with an impact on society. These include understanding the growth of neurons, generating clean energy from water, identifying proteins responsible for infectious disease, developing nano-structures for the brain, and making interfaces for quantum computation. These projects include mentors from the physics, chemistry, biology, mathematics, and psychology departments. The program will include training in user facilities, graduate school preparation, and oral/written communication. Potential participants should submit an application electronically including: a resume, college transcript, two letters of recommendation, and indication of research interests, career goals, prior experience, and preferred project. Participant selection will be conducted by the PI and Co-PI in consultation with faculty mentors. Emphasis will be placed on students interested in integrated science with an impact on society.
It is anticipated the program will train a total of 30, primarily underrepresented minority and first generation college students from schools with limited research opportunities. The REU will provide training by technical staff in user facilities, scientific communication, and will include student seminars with feedback and preparation for taking the GRE. Students will thus receive professional and scientific skills training, including opportunities to present their research at professional conferences. Combined with networkng activities and suite living, these experiences will give students a sense of belonging in STEM, along with individual and scientific growth.
A common web-based assessment tool used by all REU programs funded by the Division of Biological Infrastructure (Directorate for Biological Sciences) will be used to determine the effectiveness of the training program. Participants will be tracked after the program in order to determine student career paths. Students will be asked to respond to an automatic email sent via the NSF reporting system. More information about the program is available by visiting http://reu.bc.edu, or by contacting the PI (Dr. Burch at ks.burch@bc.edu) or the co-PI (Dr. Lowery at laura.lowery@bc.edu).
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0.915 |
2017 — 2020 |
Burch, Kenneth |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Fermi Surface Topology and the Superconducting Proximity Effect
Non-Technical Abstract: Unconventional superconductivity and the conditions under which associated physical phenomena may be observed have remained one of the most active areas of condensed matter physics. This search, began nearly 60 years ago with Meissner's original discovery of the proximity effect (induction of superconductivity into a normal material via direct contact). Interest in the proximity effect was reinvigorated by predictions of new phases and their associated particles (non-abelian anyons) that can be used for next generation topological quantum computing. The PI was the first to demonstrate a proximity effect between a high Tc, unconventional superconductor (cuprates) and a semiconductor. Building on recent success with a range of superconductors, the PI pursues the emergence of new superconducting states. Specific focus is on the role of the electronic configuration of both materials in generating proximity effects and developing new methods to probe the interface and emergent particles. Emphasis is given to diversification of the STEM workforce, including informing K-12 about 2D materials and topology via the Lynch School of Education's "Science Educators for Urban Schools" program; creating hands-on demonstrations for BC's Making Science a Fan-Tastic Experience, increasing participation of women, first generation and underrepresented minorities by partnering with BC's McNair, National Research Mentoring Network and Women in Science and Technology programs.
Technical Abstract: The proposal aims to understand the role of the Fermi surface of the normal and superconducting materials in the proximity effect. It is based on the success of the PI's mechanical bonding technique in generating a proximity effect between various superconductors and Dirac materials. The PI pursues the emergence of new unconventional/topological superconducting states. Coordinated fabrication and spectroscopic efforts provide answers to several questions in the field of proximity induced topological superconductivity: What is the role of the superconductor's Fermi surface? Does proximity induced superconductivity emerge in Weyl semimetals? Is the resulting superconductivity unconventional? Can we detect and manipulate the bound states that emerge at edges? Bound states and the proximity effect are explored as the superconductor's Fermi surface is tuned in FeTe1-xSex. Next the proximity effect are searched for in the WSM, MoTe2. The last stages employs spectroscopic probes to uncover the unconventional/topological nature of the superconductivity, along with the resulting excitations.
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0.915 |
2020 — 2023 |
Burch, Kenneth |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Understanding the Hinge Modes in a Topological Superconductor
Non-Technical Abstract: In recent years a new kind of phase of matter has been predicted, called a Higher Order topological state. This state contains specific new modes on intersections of different surfaces of the crystal. These so-called "hinge" or "corner" modes have the potential to form the basis of future topological quantum computers, immune to errors and able to perform calculations currently unthinkable. An exciting example of such materials is FeTeSe, where the PI provided the first evidence that it is a higher order topological superconductor. Using expertise in fabrication, electrical, and optical spectroscopy, the PI will develop new means to probe the properties of the hinge modes in FeTeSe systematically. The topics and techniques also provide an excellent starting point for creating public talks and recruiting a diverse set of trainees, undergraduate and graduate students, who also participate in public outreach. The project's participants gain valuable professional skills in: collaboration, computation, fabrication, and characterization.
Technical Abstract: Higher order topological phases have recently emerged, with boundary modes in two or more dimensions smaller than the bulk. These are systems whose boundary states are themselves topological, gapped with different signs. Using his expertise in fabrication, electrical, and optical spectroscopy, the PI will develop new means to probe the properties of the hinge modes in FeTeSe. An array of contact configurations and protocols will determine the best method to isolate the hinge from the bulk. This effort is aided by photothermal measurements to image the hinges. Careful studies of the effects of magnetic fields and magnetic contacts will determine the details of spin momentum locking. The studies will reveal the transport, thermal, and spin-momentum locking of the hinge modes. As such, their robustness will be directly probed, along with determining the proper ground-state Hamiltonian to describe the hinges.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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0.915 |
2021 — 2024 |
Burch, Kenneth Waegele, Matthias Momeni, Babak Zhou, Brian Ma, Qiong |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Mri: Acquisition of Thermal Scanning Probe Lithography in a Glovebox For Research and Training in Materials and Devices
This Major Research Infrastructure (MRI) award supports the acquisition of a thermal Scanning Probe Lithography (t-SPL) system in a glovebox to be housed in the Boston College (BC) Cleanroom and Nanofabrication Facility (CNRF). Combined with the Boston College “cleanroom in a glovebox”, this system allows true nanoscale fabrication entirely in inert atmosphere. This setup is relatively easy to use, has superior capabilities that come without needing to gown up, and does not demand expensive infrastructure, training, and staff required by other cutting-edge nanofabrication tools. Thus, the project allows rapid and low-cost prototyping by researchers and local companies, cutting-edge research and training of undergraduate and graduate students in nanofabrication, and will be incorporated into summer programs and classes. The system is employed for an array of basic, applied, and interdisciplinary research at BC and the region including quantum materials, catalysis, microbial interactions, biological and chemical sensors. The Nanofrazor, thermal Scanning Probe Lithography system inside a glovebox uses a thermal tip to both characterize the surface and remove the resist. As such the Nanofrazor minimizes the need for developer, produces superior surfaces to e-beam lithography (EBL) with competitive feature sizes (≈15nm), operates in a glovebox, and 3D writing (≈1nm height resolution). The minimal fabrication impact on the sample and operation in a glovebox provide new capabilities in cutting-edge 2D heterostructures and quantum materials that are often highly air sensitive. The t-SPL also provides novel device architectures requiring excellent contacts, 3D plasmonic structures, and small scales. These efforts together with the ability to rapidly fabricate new heterostructures (MBE/2D materials) and compounds with transfer via vacuum suitcase and a suite of characterization capabilities (diamond Nitrogen-Vacancy (NV) center, photocurrent, STM, TEM, Raman, magneto-transport) will amplify the impact of the t-SPL system.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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0.915 |
2021 — 2023 |
Burch, Kenneth |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Support For the Low Energy Electrodynamics in Solids Conference 2021
Nontechnical Abstract: This proposal seeks support for the participation of graduate students and young postdocs in the 2021 Low Energy Electrodynamics in Solids (LEES) international conference, June 27th to July 2nd, at the Westin in Portland, Maine. The objective of the conference is to provide a forum for exchange of ideas, novel concepts, and unpublished results in the interdisciplinary research on low-energy electrodynamics in solids and in exotic condensed phases. Experts in a wide range of theoretical and experimental techniques focused on the electrodynamics of quantum materials will join with up and coming junior researchers. The program is organized to allow for a range of interactions and discussions, as well as opportunities for junior participants to share their work. Fifteen invited speakers are graduate students, postdocs or new faculty. The organizers are making significant efforts to have participation from members of underrepresented groups including providing support for child care, diversifying the organizing committees and speakers (ten invited speakers are women, three are LatinX).
Technical Abstract: Scientifically, there will be an emphasis on the electronic and magnetic properties of quantum materials and their applications for future technologies. Discussion will encompass both theoretical and experimental methods including: broadband, time-resolved and near-field optical and photoemission spectroscopies, nuclear magnetic resonance, inelastic neutron/X-ray scattering, and scanning tunneling microscopy. It is highly timely to hold such a conference with a focus on coordinating the unprecedented ability to create, probe and control topological and correlated states of matter. Indeed, many of the unique states of quantum materials result from the entanglement of magnetic, lattice, and electronic properties. As such no single technique can unravel their origins, let alone control them for future incorporation into cutting edge devices. This conference will bring together a wide range of disciplines and focus on both theoretical and experimental methods.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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0.915 |
2022 — 2025 |
Burch, Kenneth |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Nsf-Bsf: High-Temperature Superconducting Photon Detectors
This proposal aims to enable quantum limited photon sensitivity in practical applications by developing superconducting nanowire photon detectors based on high-temperature superconductors (high-Tc). To date such sensitivity is achieved with standard superconductors operating at extremely cold temperatures. Nonetheless such sensors offer the ultimate sensitivity needed in quantum communications, chemical detection, and low light imaging. High-Tc cuprates could achieve such performance above liquid nitrogen, offering a revolution in the practicality of such devices. While these materials have been studied for decades, they are quite sensitive to the typical approaches to making devices. The fundamental limitations in making such devices will be studied and overcome via a collaboration between the groups of Alex Hayat (Technion), and the group of Kenneth Burch (Boston College-BC). Specifically, they will use recent advances in the thin film growth of these materials, single atomic layer graphene as a protective coating and fabrication in inert atmosphere to uncover the origin of material degradation and methods to protect the high Tc for fabrication into optical sensors. In addition, the effort will enable a range of diverse trainees to be exposed to cutting fabrication and optical techniques as well as topics at the forefront of quantum communications. <br/><br/> High Tc cuprates have been extensively studied over the years, with a focus on the underlying mechanisms of their magnetic, strange metal and superconducting responses. In addition, substantial efforts have focused on using the cuprates for low loss electrical transmission. This project focuses instead on the fundamental challenges to incorporating these materials in optoelectronic devices and quantum optics experiments. Specifically, the team will investigate new methods of preparing templates for selective area growth of YBCO films. They will also explore the use of CVD graphene as a protective layer on the films to minimize damage in fabrication. Both will involve the use of a cleanroom in a glovebox to minimize atmospheric contamination. In addition to standard e-beam lithography, thermal scanning lithography will be attempted to reduce unwanted damage. Ultimately the resulting films and devices will be characterized by a range of the techniques (EDX, Raman, AFM, TEM) to uncover the mechanisms limiting performance. In addition, the quantum detector properties will be measured to reveal the key parameters governing the performance for quantum limited photon sensitivity.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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0.915 |