Athos Petrou - US grants

The PI will use reflectivity and magneto-reflectivity spectroscopies for the study of GaAs/AlAs quantum wells, grown at the U.S. Army Electronic Devices and Technology Laboratory (EDTL), in collaboration with Dr. Mitra Dutta. A graduate student will participate in the sample growth process, at EDTL, as well as in some of the characterization experiments there. The objective of the proposed work is to determine a number of parameters of GaAs/AlAs quantum wells. Specifically we intend to measure: (a) the effect of confinement and strain on the band structure, (b) the electron effective mass inside the wells, and (c) exciton binding energies. These parameters are crucial for the design and modeling of electronic devices that incorporate these heterostructures. Since no magneto- optical set-up is available at EDTL, we hope that this joint project will help the crystal growth and characterization effort there.

The PI proposed to examine short period GaAs/A1As quantum well, with emphasis in the type I to type II transition. Two related structures will be examined. (i) GaAs/A1GaAs quantum wells in which the conduction subband separation is tuned in the infrared, by the presence of a narrow barrier grown at the center of the well. (ii) Shallow GaAs/A1GaAs quantum well structures in which the application of an external magnetic field will tune the electronic states outside the GaAs layers. The proposed research will be carried out in collaboration with Dr. Mitra Dutta (ETDL). The samples will be grown at the U.S. Army ETDL facility using MBE. A graduate student from SUNY will travel to ETDL and participate in the TEM characterization of the structures.

Research on GaAs/A1As quantum well structures will be conducted in collaboration with Dr. Mitra Dutta and her co-workers at U.S. Army Electronic Technology and Devices Laboratory (ETDL), Fort Monmouth. The program will emphasize study of GaAs/A1GaAs quantum wells perturbed by the addition of thin A1As barrier at the center of each well using reflectance and photoluminescence spectroscopies. The goal is to explore a new method of tuning intersubband transition energies for FIR detector applications.

This research is concerned with studies of zinc-selenide/zinc- iron-selenide quantum well structres and zinc-iron-selenide epilayers of high quality which have been grown by molecular beam epotaxy (MBE) technique. These structures have the unusual property that the hole confinement is determined by an externally applied magnetic field. This situation leads to a novel situation concerning the different types of excitons which has never been observed in a dilute magnetic semiconductor. The zinc-selenide/zinc-iron-selenide system offers a unique opportunity to tune the quantum well potential and control the carrier confinement using an external magnetic field. Magneto- reflectance and magneto-luminescence spectroscopy measurements will be made exploring the parameter space of this system (layer thickness, iron concentration, number of wells) as well as the dependence on temperature and magnetic field. These magneto- optical studies will also be extended to doped systems.

9311835 Petrou We propose a magneto-optical study of the following two semiconductor microstructures: (a) GaAs/ALAs quantum wells dopes n-type in the A1As barriers. We plan to investigate structures for which th lowest conduction subband lies a few meV below the Silicon donors. (b) ALAs/ALGaAs quantum wells doped n-type in the ALGaAs layers. We propose to investigate the properties of the two-dimensional electron gas confined in the ALAs layers. ***

This research project addresses the magneto-optic response of ZnSe- based quantum well structures incorporating diluted magnetic semiconductor (DMS) layers such as ZnFeSe or ZnMnSe. DMS-based heterostructures are unique among semiconductor quantum wells in that the band offsets between layers can be tuned continuously via the application of an external magnetic field. The project also involves the preparation an study of new magnetic alloys based on zinc, manganese, iron and selenium. The materials can be viewed as two phases, one being a Brillouin paramagnet, the other being a Van Vleck paramagnet. The two phases lead to novel magnetic behavior which can be tuned by varying temperature and the external magnetic field. %%% This research project involves the synthesis and characterization of new semiconducting materials which are also magnetic. These unusual materials have optical properties that vary when they are placed in a magnetic field. These properties offer promise in microwave and information storage technologies.

9722625 McCombe This is a new project in which optically Detected Resonance (ODR) spectroscopy, which combines the sensitivity of near IR/visible photon detection with far IR excitation, will be used to investigate basic issues related to many-body interactions of electrons and holes in low-dimensional semiconductor systems. Intraband electronic excitations of very low densities of photoexcited carriers and carrier complexes can be investigated in this way. Specific projects include: internal states of neutral and charged excitons in high magnetic fields; effects of excess electrons and holes on excitonic states and the metal- insulator transition; many body effects in the integer and fractional quantum hall effect regimes through the influence of donor impurities on the far IR excitations; and ODR echanisms. This research will yield unique information about excitons, effects of excess carriers on their internal states, mechanisms of energy ransfer to the ground state recombination paths, and insight into the any-body ground states of electrons at low temperatures and high magnetic fields. %%% This is a new project in which a novel technique that combines sensitive near infrared/visible detection with resonant absorption in the far infrared region of the spectrum, Optically Detected Resonance (ODR) spectroscopy, will be used to investigate the allowed energy states of charge carriers in small (tens of nanometers) man-made semiconductor structures. The unique electronic and optical properties of these structures are determined by quantum mechanics and the interactions of the charge carriers, electrons or holes. This research will yield unique information about and improved understanding of the energy states of electrons and holes bound together (the so-called exciton), the effects of excess free electrons and holes on these states, and how e nergy absorbed in exciting the electron-hole system is transferred back to the lowest energy states and subsequently leads to recombination and light emission. This work will also provide insight into the interesting many-electron states that exist at low temperature and in high magnetic field, the Quantum Hall and Fractional Quantum Hall states. ***

9802875
McCombe
Semiconductor quantum wells (QWs), quantum wires and quantum dots are currently of great interest, and optical and infrared (IR) techniques have been central to developing an understanding of the electronic states, excitations and interactions in these low-dimensional semiconductor structures. Optically detected resonance (ODR) spectroscopy, an approach which combines the sensitivity of visible/near IR photon detection with far IR excitation, and which alleviates many of the problems alluded to above, has recently been developed, and extended and used for the first time by the co-investigators to study neutral and negative donor ions in doped QW's and internal transitions of photocreated excitons in QWs. These results demonstrate the promise of ODR spectroscopy for studies of low-dimensional semiconductor structures.

Based on our experience with the conventional ODR approach and our recent demonstration experiments with a borrowed spectrograph/CCD array system, we will acquire a high sensitivity, high resolution mated spectrograph/CCD array system with acquisition and analysis software for full-spectrum ODR spectroscopy studies of semiconductor nanostructures. This system will be used to investigate several basic issues related to the electronic states of low-dimensional semiconductor structures in high magnetic fields. The project involves the collaboration of two senior investigators whose combined expertise spans optical studies of low-dimensional semiconductor structures in the III-V and II-VI materials systems from the far IR to the visible. Specific problems to be investigated include: internal states of negatively and positively charged excitons and cyclotron resonance of charged excitons; effects of excess electrons and holes on the excitonic states and the metal-insulator transition; many-body effects in the integer and fractional quantum Hall effect regimes; and application of ODR to the study of impurity and free carrier electronic states in quantum wires and quantum dots. We anticipate that the proposed system will greatly enhance both the quantity and quality of these experiments, and the education and training of our students.
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0076466
Markelz

This grant supports the acquisition and use of a versatile, optical-access, high-field (10T), split-coil superconducting magnet system for experimental investigations of quantum dots and quasi-two-dimensional excitons in semiconductors, and the dynamical conductivity of high Tc superconductors. This research is directed at achieving an understanding of several outstanding physics problems: 1) Internal transitions of excitons in lateral fluctuation quantum dots in GaAs/AlGaAs, 2) dynamics of photoexcited neutral excitons in GaAs/AlGaAs quantum wells, and 3) the dynamical conductivity and relaxation times in high temperature superconductors (HTSC) in the mid-infrared and terahertz regions of the spectrum. An improved understanding of the behavior of the fundamental optical excitation of low-dimensional semiconductor structures, the exciton, which may be important in implementations of quantum computation, is also expected to be developed from these studies. In addition, this research will provide insight into one of the fundamental conundrums of high temperature superconductor materials, the apparent non-Fermi liquid transport behavior in the normal state.

This project supports the acquisition of a high magnetic field, optical access, cryogenic system to enable unique optical studies of materials systems of fundamental and technological interest using our existing versatile optical systems that range in frequency from the microwave to the ultra violet. We will initially focus on two materials systems:
quantum confined electronic structures in semiconductors and high temperature superconductors. This research is directed at achieving an understanding of several outstanding physics problems: 1) Internal transitions of excitons in quantum dots in GaAs/AlGaAs, 2) dynamics of photoexcited neutral excitons in GaAs/AlGaAs quantum wells, and 3) the dynamical conductivity and relaxation times in high temperature
superconductors (HTSC) in the mid-infrared and terahertz regions of the spectrum. These studies will improve present day understanding of the behavior the fundamental optical excitations of low-dimensional semiconductor structures, which may be important in implementations of quantum computation. In addition, this research will provide insight into the origins of high temperature superconductivity.

This is an Information Technology Research Proposal (ITR). Until recently, an intrinsic property of electrons, their spin, has been overlooked in potential applications in electronics. Understanding and manipulating spin in appropriate semiconductor structures offers promise for entirely new types of future "spintronic" devices and for producing elements of quantum computers. "Spintronic" devices are non-volatile, consume less power, and can be faster than conventional electronic devices that are based on the charge of the electron. This project will focus on investigating the complex states of electrons and holes and their interactions with the local environment in semiconductor quantum structures that have potential for application in spin-based devices which ultimately might find their way into future quantum spin based computers. An array of optical techniques will be used to probe spin-related effects in semiconductor nanostructures. The project will couple extensive experimental investigations with theoretical calculations and predictions. Three graduate students, one undergraduate student and one or more high school physics teachers will be involved in these projects. Results are expected to reveal new physics and bring improved understanding to issues that will be important for implementing future generations of devices for information technology.

This is an Information Technology Research proposal (ITR). Until recently the carrier spin has been overlooked in electronic devices. Understanding and exploiting carrier spin in semiconductors offers promise for spintronic devices, which are non-volatile, consume less power, and can be faster than devices based on manipulation of carrier charge. This project couples experimental and theoretical research directed at understanding and manipulating spins in semiconductor structures. The detailed nature of electronic states of neutral and spin-singlet/-triplet charged excitons in GaAs/AlGaAs lateral fluctuation quantum dots will be investigated with the goal of understanding their role in possible implementation of quantum bits. The spin states of carriers in spin-injection devices will be probed with the goal of understanding the effects of lattice vibrations, band structure, phonons, interfaces and diffusion distances on the degree of spin polarization. Polarized photoluminescence (PL) and PL excitation spectroscopies combined with optically detected resonance (ODR) spectroscopy of free electrons and holes, and internal transitions of excitons will be employed in these studies. Three graduate and one undergraduate students, one or more high school physics teachers will be involved in these projects. Results are expected to reveal new physics and bring improved understanding to issues that are important for future information technology applications.

This proposal was received in response to the Spin Electronics for the 21st century Initiative, Program solicitation NSF 02-036. The proposal focuses on the study of spin injection phenomena in a variety of spin Light Emitting Diodes (spin-LEDs). The proposed work has an experimental as well as a theoretical component. All the devices that will be used in the experimental part of this proposal have an AlGaAs(n)/GaAs/AlGAs(p) light emitting diode at their core. The circular polarization of the diode emission is used to determine the relative spin population of carriers confined in the GaAs layer. In ZnMnSe based spin-LEDs the ZnMnSe contact layer is the source of spin polarized electrons. In this well studied system we will explore the effects of resonant heating of the electrons and holes at various components of the device using far infrared (FIR) monochromatic light. Choice of FIR wavelength and of the externally applied magnetic field allows the study of the effects of heating on the diode output of a particular carrier (electron or hole) in a specific component of the device (GaAs, AlGaAs or ZnMnSe layer) . In addition we will be using specially designed, n-type modulation doped ZnMnSe spin LEDs to study the population statistics of electrons confined in the GaAs quantum well of each diode and occupying a number of Landau levels. The second type of spin-LED will use a ferromagnetic layer as spin polarized electron source with the easy magnetization axis perpendicular to the layer axis. Such a device is expected to require only a few hundred Gauss to operate, as opposed to a few tesla required by the recently developed Fe-based spin LEDs in which the easy magnetization axis lies in the Fe layer plane. Finally we plan to explore AlGaMnAs as a potential spin polarized hole injector.

In the theoretical component of this proposal we describe investigations of several important phenomena that take place in spin injection LEDs and affect the operation and efficiency of these devices. We propose to investigate the capture process of the carrier in the GaAs wells and the subsequent energy relaxation to the lowest confinement subbands e1 and h1. The role of phonon emission and the associated spin-flip processes will be explored.

A very close and synergistic relationship between the experimental and the theoretical components of the proposed work is expected to contribute to the success of the project.

An educational aspect of the proposed work will involve two undergraduate students in the program (from Physics and/or EE) working closely with graduate students and the co-investigators. Support for the undergraduate students will be requested from the REU program

The objective of this research is to investigate materials that can inject efficiently electrons of predominantly one spin state into semiconductor devices. The approach is to explore the following promising systems. 1) Side emitting Fe-based spin light-emitting diodes. These require very small magnetic fields for their operation. The side emitting geometry offers the possibility for the development of spin lasers. 2) InAs quantum-dot-based light-emitting diodes with Fe spin-injecting contacts. These devices can operate at room temperature due to the zero-dimensional character of the InAs quantum dots. 3) InAs-based spin light-emitting diodes. This material system offers high electron mobility for optical applications in the mid-infrared. 4) A new class of spin light-emitting diodes which utilize half metallic MnAs layers as spin injecting contacts.

The proposed program combines scientific research with education and outreach to the local high schools. In the former category we expect that the proposed scientific work, will have a significant impact on the future development of information technology due to the potential use of the results for practical applications in spintronic devices. Some aspects of the proposed work on InAs quantum dots are also expected to find applications in the emerging, and related, field of quantum computing. The educational aspect of the work has two directions: 1) training the next generation of scientists and engineers in the emerging field of spintronics; and 2) disseminating information on the scientific method in general and on the proposed work in particular to students at the high school level.

Engineering - Electrical (55)
This CCLI Phase I exploratory project involves an interdisciplinary Nanoelectronics Laboratory for the Engineering/Science Undergraduate Curriculum. The project team is developing a set of ten laboratory experiment modules for a target audience of second-year science and engineering undergraduate students. The experiments include the use of scanning probe microscopy (SPM), the study of electron diffraction, absorption of light by quantum dots and photoluminescence from quantum dots. The hands-on laboratory course is complementing a recently developed lecture-based course funded by Nanotechnology Undergraduate Education. Anticipated outcomes for science and engineering undergraduate students include: an understanding of fundamental concepts involved in nanotechnology; hands-on experience using advanced tools to characterize, analyze, and synthesize experimental results; and increased awareness of career opportunities in the area of nanotechnology. Both formative and summative evaluation methods are used in project assessment. Evaluation efforts are coordinated by a faculty member in the area of Science Education. The project also includes faculty from two Community colleges assisting in the development, implementation, and dissemination of the course as well as active participation by the team in the development of an interactive exhibit on nanotechnology and K-12 science teachers to perform experiments related to the exhibit.

Objectives: The objectives of this research program are: 1) to obtain efficient spin injection into InAs at elevated temperatures by exploiting favorable structural, magnetic and electrical properties of ferromagnetic MnAs contacts grown in the zinc-blende structure on InAs-based materials; 2) to develop a usable all semiconductor spin injector by exploiting the Rashba effect in InAs and employing resonant tunneling from an InAs quantum well into an (InGa)As detector under a bias-created electric field; 3) to improve the efficiency and temperature robustness of spin injection from recently developed Fe/GaAs spin light emitting diodes (LEDs) which incorporate ultrathin InAs layers embedded in the GaAs Quantum wells. The approach is to measure the circular polarization of the electroluminescence emitted by these devices from which the injected electron spin polarization and therefore the device efficiency will be determined.

Intellectual merit: There are considerable challenges in the design and growth of suitable structures for each of the projects to be undertaken. These challenges include the growth of the necessary structures, and understanding how the various growth parameters affect the outcome and how they can be controlled.

Broader Impact : If this research is successful, it will have a significant impact on the field of spintronics, and thus possible future generations of information technology, by providing suitable efficient injection structures for both GaAs-based and InAs-based devices. An outreach program directed at high school students with the objective of providing them with exposure on the principles of wave-mechanics and its applications in nanostructures will be offered.

Engineering - Electrical (55)

This project is developing new course materials to teach quantum mechanics to junior engineering students. The course materials include course lectures, laboratory experiments and a textbook. The materials are being developed using a bottom-up approach that begins with the analysis of quantum dots and then moves on to two-dimensional and three-dimensional quantum objects. The new course utilizes some educational materials in nanoscience and nanoelectronics developed under the NSF Nanotechnology Undergraduate Education program. The new course is designed such that it could replace the third physics course that is common in electrical engineering curricula. The course also serves as a gateway to senior level elective courses in nanoelectronics and related areas. The project includes a detailed formative and summative evaluation plan led by an independent evaluator. The evaluation plan is designed to assess the quality of the materials being developed and their impact on student learning. The course and lab materials are being disseminated through conferences and a web site. The project includes outreach to high schools through an established summer workshops for high school students program.

Technical: Many currently studied spintronics devices involve spin injection from ferromagnetic materials into nonmagnetic semiconductors. Recent studies show that significant diffusion occurs when Mn and Fe containing ferromagnetic metals are grown on GaAs or Si. There are also recent reports showing evidence of spin scattering after spin-polarized carriers are injected into nonmagnetic structures. It is therefore important to investigate this problem systematically, so that the analysis of injection results can be improved. This project focuses on diffusion of magnetic ions in the most studied systems, namely Fe/GaAs, FeCo/GaAs, MnAs/GaAs and GaMnAs/GaAs, and on selected structures involving silicon. The samples are grown by molecular beam epitaxy. Diffusion profiles are determined using time-of-flight second ion mass spectroscopy and cross sectional scanning tunneling microscopy. The effect of diffused magnetic ions on spin injection is primarily determined with spin light emitting diode structures, which have been effective in determining the level of spin polarization of the injected electrons. The study is designed to provide quantitative information concerning the profile of diffused magnetic ions in nonmagnetic semiconductors, and their effect on spin injection. By examining diffusion as a function of temperature through annealing, one is able to put upper limits on growth and device processing temperatures. The project also explores the possibility of suppressing diffusion processes for the magnetic ions.
Non-technical: This scientific work could have a significant impact on the development of future generations of information technology. It addresses a common issue that exists in most studies of spin effects involving transport of spin polarized currents from one material to another. This would include studies of spin light emitting diodes, spin lasers, spin valves and other more complicated spin-logic devices that involve ferromagnetic materials. The project also contributes to training the next generation of scientists by adding another venue to provide interdisciplinary training to students for the three investigators who have a long history of jointly advising graduate students in physics and chemistry. In addition, the project involves outreach to the Native American Magnet School (K-8) in Buffalo and engages, at an early stage, Native American and African American students in sciences and engineering.

With this award from the Major Research Instrumentation (MRI) Program that is co-funded by Chemistry, Professor Frank Bright from SUNY Buffalo and colleagues Joseph Gardella, Athos Petrou, Esther Takeuchi and Sarbajit Banerjee will acquire a tip-enhanced Raman spectroscopy (TERS) system. The proposal is aimed at enhancing research training and education at all levels, especially in areas such as (a) nanocrystalline sensor platforms, (b) vanadium dioxide and metal vanadate (MxV2O5, where M = Na, K, Cu, Zn) nanowires, (c) biodegradable repair and delivery constructs, (d) magneto-polarons within single ZnMnTe quantum dots, (e) advanced energy storage materials, (f) nanodiamond-based separations, (g) nanoscopic heterogeneity within antifouling and fouling release film surfaces, (h) hydroxyapatite nucleation and growth, (i) organic nanotubes and periodic nanomaterials, (j) substrate-catalyzed monolayer photolithography and energy-conversion, (k) photo-crystallization within amorphous selenium, (l) development of terahertz technologies based on graphene heterostructures, and (m) flexible hybrid xerogel/Bragg grating platforms for wound sensing and restitution.

Raman spectroscopy is a vibrational spectroscopy technique that serves as a powerful analytical tool to identify sample structures. However, the intensity of normal Raman spectroscopy is not very strong and thus ways to enhance the signal are essential. The tip-enhanced Raman spectroscopy (TERS) method is based on the combination of Raman spectroscopy, surface enhanced Raman scattering (SERS) and atomic force microscopy (AFM). The TERS effect uses a metal-coated AFM tip as an antenna that enhances the Raman signal coming from the sample area in contact with the tip. Because the AFM tip is on the nanometer scale, it is possible to obtain localized enhancement on the same scale. By differentiating the tip enhanced Raman from the normal Raman (tip away from the sample) it is possible to obtain Raman information from areas <100 nm in diameter. The requested TERS system will facilitate the characterization of thin films, nanostructures, and porous surfaces and will serve to train undergraduate and graduate students, as well as postdocs. It will also be used in outreach activities at the K-12 level.

PROJECT DESCRIPTION

This project is developing a one-semester Electromagnetic Fields and Waves (EFW) course for junior-level engineering undergraduate students and is establishing a new undergraduate laboratory for teaching EFW. The project is creating a novel teaching approach that employs interactive pedagogies, exposing students to an educational sequence of experimentation - theory - experimentation - applications. Undergraduate students are using experiments, educational Java applets, and numerical solver software to help them learn the theoretical principles of EFW. Through the utilization of engaging teaching practices, students are also learning to utilize a scientific approach and further develop their critical reasoning and creative thinking skills.

The understanding of electricity and magnetism requires a certain level of mathematical knowledge; therefore, concepts such as vector algebra and vector calculus are gradually introduced - as needed - in sync with the teaching material that is covered in the course. The teaching approach involves the following: 1) a non-traditional synergistic style of teaching and use of an interactive Blackboard online system (UBlearns); 2) an introduction to electricity and magnetism that is provided through a student's exploration of corresponding experiments; and 3) a unified description of the entire electromagnetic spectrum, which is used to provide an appreciation for interdisciplinary applications.


BROADER SIGNIFICANCE

The project is attempting to positively impact the recruitment of high achieving K-12 students to STEM education, the training of college professors, and the involvement of women and underrepresented minority undergraduate/graduate students in the development of a new EFW laboratory. The results are being disseminated through participation in ASEE conferences and workshops, while the developed teaching materials and lab manuals are being distributed to college/university professors. A newly developed course website offers the results of the project activities along with the teaching materials and lab manuals. The teaching strategies are embedded in a new textbook/lab manual publication to further enhance STEM education. The team is additionally working with local chapters of the Association of Black Engineers and Applied Scientists, the Society of Hispanic Professional Engineers, and the Women in Science and Engineering to recruit engineering students from underrepresented groups.

****Technical Abstract****
The research in this project will develop improved understanding of novel magnetism created by optical excitation in type-II (II-Mn)-VI quantum dots, and will explore controlling magnetic properties by optical beams. Recently discovered optical and magnetic phenomena in these type-II quantum dots, as well as interesting re-entrant magnetic states predicted by theory collaborators will be investigated. The research program involves MBE growth, structural, compositional and magnetic characterization, CW and time-resolved interband magneto-optical spectroscopy and terahertz intraband spectroscopy of ensembles and single quantum dot columns, as well as associated theory. This effort will lead to a better understanding of the basic physics and materials issues of these type-II columnar quantum dots in the (II,Mn)-VI materials systems. The PIs at UB will host an Interdisciplinary Science and Engineering Partnership (ISEP) supported teacher in interdisciplinary research in their laboratories with the objective of expanding opportunities to link materials and solid state physics research to the middle and high school classroom. In addition, building on previous success, a one-week summer workshop in the second summer of the grant to provide an introduction to magnetic phenomena and their application to everyday devices will be conducted; high school teachers from the area will participate.

****Non-Technical Abstract****
This project will explore controlling magnetic properties of nanostructures using optical beams. The research team involves two senior co-PIs and theory collaborators from the University at Buffalo, a co-PI at the University of Oklahoma and collaborators in MBE growth at the National Chiao Tung University, Taiwan. The PIs will explore novel magnetic states in quantum dots that incorporate magnetic ions such as manganese. These magnetic quantum dots will serve as platform for inducing, manipulating and controlling magnetism by light. The effort will lead to a better understanding of the basic physics and materials issues of these quantum dot systems. The experiments, which will ultimately focus on individual columns of dots, are challenging, and there is a great deal of interesting physics predicted to occur in these systems, as well as likely unanticipated discoveries. The PIs at UB will host an Interdisciplinary Science and Engineering Partnership (ISEP)-supported teacher in interdisciplinary research in their laboratories with the objective of expanding opportunities to link materials and solid state physics research to the middle and high school classroom. In addition, building on previous success, a one-week summer workshop in the second summer of the grant to provide an introduction to magnetic phenomena and their application to everyday devices will be conducted; high school teachers from the area will participate.

This cryogen-free system with its superconducting magnet and wide sample temperature range capabilities for magneto optical and magneto transport measurements in a wide range of frequency builds on faculty expertise at the University at Buffalo SUNY (UB), strongly supports existing research programs and will serve as a user facility for the current members of UB community and proposed new faculty hires in the general area of Material Science and Engineering. The system will allow UB researchers to expand their research activities into a broad range of new applications, such as new electronic, photonic, spintronic, and energy devices, and thus, enhance existing grants while positioning them well for investigation of novel materials. This system will allow interdisciplinary research training for the undergraduate and graduate students and postdocs. The proposed system will be accessible to researchers in the fields of nanoelectronics, semiconductor physics and energy related research from the community colleges and start-up companies in the Buffalo area. This training is valuable for the students in the western New York region for their future careers in high tech industry, academia and in national laboratories.

This Major Research Instrumentation award supports and enhances the interdisciplinary research activities of several research groups at the University at Buffalo, SUNY (UB) through the acquisition of a cryogen-free magnet cryostat system with optical and electrical measurement capabilities. The research activities range from transport measurements on nanoscale oxide materials near phase transitions, mesoscopic phenomena in semiconductors and two-dimensional (2D) materials, growth and characterization of 2D transition metal dichalcogenides (TMD), the interplay of disorder and topologically-protected transport in 2D materials, magneto reflectance and polarization measurements on TMDs, Hall effect in superconductors, THz emission from 2D materials and heterostructures, and next generation power devices. With a potential to perform concurrent optical (from UV to mid-IR frequency range) and transport (both AC and DC) measurements, the system will serve a wide user base with varied technical needs. This cryogen-free magnet system will enable all UB researchers, including underrepresented minorities and women within our diverse academic community, to access its state-of-the-art capabilities.