Shopping cart

close

Past Events

Event Date Summary
Wei-Cheng Lee, Binghamton University-SUNY, Orbital Selective Mott Transition in Thin Film VO2 Mon. April 23rd, 2018
12:45 pm-1:45 pm

Orbital Selective Mott Transition in Thin Film VO2

Wei-Cheng Lee

Department of Physics, Applied Physics, and Astronomy, Binghamton University – SUNY

In this talk, evidences of strain-induced modulation of electron correlation effects in the rutile phase of epitaxial VO2/TiO2 will be presented. The strain is engineered by different growth orientations (001), (100), and (110). We find that the hard x-ray photoelectron spectroscopy (HAXPES) reveals significant suppression of the density of states at the Fermi energy in (100) and (110) samples at a temperature well above the metal-insulator transition temperature, but not in the (001) sample.

Fac. meeting Mon. April 16th, 2018
12:45 pm-1:45 pm
Susan Fullerton, University of Pittsburgh, Using Ions to Control Transport in 2D Materials Mon. April 2nd, 2018
12:45 pm-1:45 pm

Using Ions to Control Transport in 2D Materials

Susan Fullerton, University of Pittsburgh

 

Electrostatic gating of two-dimensional (2D) materials with ions is an effective method to achieve high carrier density (10^13 – 10^14 cm^-2) and excellent gate control by creating an electric double layer (EDL) with large capacitance density (>2 μF/cm^2). I will review our use of EDL gating to investigate transport properties of 2D materials including MoTe2, MoS2 and WSe2, and introduce new device concepts that employ EDL gating as an active device component. These include a monolayer electrolyte for application in flash memory,

Olle Heinonen, Argonne National Laboratories, Quantum Monte Carlo modeling of real materials Fri. March 30th, 2018
3:30 pm-4:30 pm

Quantum Monte Carlo modeling of real materials

Olle Heinonen, Argonne National Laboratory

 

Because of recent advances in algorithms and hardware, it is now possible to do quantum Monte Carol simulations of real materials systems, such as correlated oxides, for which standard density functional theory methods have well-known problems. I will here briefly introduce variational and diffusion Monte Carlo methods, and then discuss some results for correlated oxides as well as for some chemical systems. I will end with discussing on-going developments and an outlook towards the future.

 

 

Benjamin Fregoso, Dept of Physics, Kent State University, Nonlinear photocurrents in two-dimensional ferroelectrics and beyond Wed. March 28th, 2018
12:45 pm-1:45 pm

 Nonlinear photocurrents in two-dimensional ferroelectrics and beyond

Benjamin Fregoso, Dept. of Physics, Kent State University

Abstract:

In recent years, it has become clear the need for efficiently harvesting solar energy. Unfortunately, silicon-based solar cells with high efficiency are very costly. These devices rely on pn-junctions to separate positive and negative charge carries. I this talk, I explore a less known (but very interesting) nonlinear optical effect, so-called `shift current’, to generate large photocurrent beyond the pn-junction paradigm. I will describe the shift-current mechanism in insulators and ferroelectrics and its relation to spontaneous electric polarization.

Katy Keenan Applied Physics Division, Physical Measurement Lab National Institute of Standards and Technology Quantitative MRI for Precision Medicine Thu. March 22nd, 2018
2:00 pm-3:00 pm

IMAGING PHYSICS SEMINAR

Katy Keenan
Applied Physics Division, Physical Measurement Lab
National Institute of Standards and Technology

Quantitative MRI for Precision Medicine

The ability of MRI to measure real, physical parameters of interest requires reference standards to ensure accuracy and reproducibility of data. Currently, variability exists across MRI systems, manufacturers, models, software versions, and analysis packages, which impedes comparison of data across patients, centers, and time. To move towards precision medicine, we must be able to determine the threshold of normal compared to disease state with a diagnostically useful uncertainty.

Debra McGivney, Dept. Radiology CWRU, Inverse Problems in Medical Imaging Tue. March 20th, 2018
1:00 pm-2:00 pm

IMAGING PHYSICS SEMINAR
Debra McGivney
Research Scientist, Department of Radiology
Case Western Reserve University

Inverse Problems in Medical Imaging

Mathematical inverse problems are used to model a wide variety of practical problems, including problems in medical imaging. Here, the unknown of interest is an image of the inside of the human body, which is not directly observable, but must be reconstructed given measurements made outside of the body. Oftentimes, reconstruction problems in imaging are ill-posed, which can result in errors in the reconstructed solution. Medical imaging plays a vital role in the diagnosis,

Yuan-Ming Lu, The Ohio State University, Tunable Surface States of Topological Materials Mon. March 19th, 2018
12:45 pm-1:45 pm

Tunable Surface States of Topological Materials

Yuan-Ming Lu, The Ohio State University

 

The discovery of topological insulators revealed a large class of topological materials, which exhibit novel surface states with unusual properties. I will discuss some recent progress in engineering surface states of topological materials, focusing on two different systems. The 1st class of materials is three-dimensional Dirac semimetals including Na3Bi and Cd3As2, whose topological surface states can be deformed in these materials by either doping or applying mechanical strain. The 2nd class of materials are spin-orbit coupled quantum magnets,

Alexey Tonyushkin University of Massachusetts Boston, Breaking the Rules in Magnetic Particle Imaging and Ultra-High Field MRI Thu. March 15th, 2018
12:30 pm-1:30 pm

IMAGING PHYSICS SEMINAR
Alexey Tonyushkin
University of Massachusetts Boston
Breaking the Rules in Magnetic Particle Imaging
and Ultra-High Field MRI

Magnetic Particle Imaging (MPI) is a new tomographic imaging modality that offers high spatial and temporal resolution. Compared to the other imaging modalities such as MRI/CT/PET, MPI is non-toxic, more sensitive, and fully quantitative technique. To date a few small-bore MPI systems were developed, however, human-size MPI scanner has yet to be built. The major challenge of scaling up of MPI is in high power consumption that is associated with the traditional approach to designing the scanner.

Spring break ( no seminar) Mon. March 12th, 2018
12:45 pm-1:45 pm
Michael Boss, NIST, Quantitative MRI: from Bench to Bedside Mon. March 12th, 2018
4:30 pm-5:30 pm

IMAGING PHYSICS SEMINAR
Michael Boss
National Institute of Standards and Technology
Quantitative MRI: from Bench to Bedside

Quantitative MRI: from Bench to Bedside Magnetic Resonance Imaging (MRI) is an exquisite tool for probing the anatomical structure of the human body. It is also capable of measuring physical parameters such as relaxation times, diffusion and temperature, known as quantitative imaging biomarkers (QIBs). When acquired using methods with known limits of bias and reproducibility, these QIBs allow for comparison of scan data across patients, imaging sites, and time, turning into a powerful tool for clinical trials and patient care to evaluate disease state and treatment response.

APS March Meeting ( no seminars) Mon. March 5th, 2018
12:45 pm-1:45 pm
APS March Meeting preview: student practice talks Mon. February 26th, 2018
12:30 pm-2:00 pm

Shuhao Liu:  A Temperature Driven Hole-phonon Coupling Enhancement Effect in a Strongly Correlated 2D Hole System.

Kasun V. M. N. G. Premasiri:  Tuning Rashba Spin-orbit Coupling in Few-layer InSe.

Kyle Crowley: Doping and Field Effect in Novel 2D Layered Oxides

Santosh Kumar Radha: Distortion modes in inorganic halide perovskites: to twist or to stretch.

Narasak Pandech: First-principles Investigation of The Role of Organic Molecules Inside The α-phase of Hybrid Halide Perovskite CH3NH3BX3 (B= Pb,

Andrew Stephens, Northwestern U., Separating the role of chromatin from lamins in mechanics and morphology of the cell nucleus Thu. February 22nd, 2018
4:30 pm-5:30 pm

Separating the role of chromatin from lamins in mechanics and morphology of the cell nucleus

Andrew Stephens, Northwestern U.

The nucleus is the 10 µm ellipse compartment in the cell which must properly transduce or resist biophysical
forces to dictate the spatial organization of the 2 meters of genome inside of it. Organization and
mechanotransduction determine the expression profile of genome which dictates cell function. Previous studies
revealed that the two major contributors to nuclear mechanics are lamins, protein intermediate filaments lining
the inner nuclear envelope, and chromatin, the DNA genome and its associated proteins,

Fac. meeting Mon. February 19th, 2018
12:45 pm-1:45 pm

No seminar physics fac. meeting

Lydia Kisley, Univ. Illinois at Urbana-Champaign, Proteins in nanoporous hydrogels: adsorption, diffusion, and folding Mon. February 19th, 2018
4:30 pm-5:30 pm

Proteins in nanoporous hydrogels: adsorption, diffusion, and folding

Lydia Kisley
Beckman Institute, University of Illinois at Urbana-Champaign
Abstract:  Proteins within nanoporous hydrogels have important biotechnological applications in
pharmaceutical purification, tissue engineering, water treatment, biosensors, and medical
implants. Yet, oftentimes proteins that are functional in solution lose activity when in contact
with soft nanostructured materials due to perturbations in the folded state, conformation,
diffusion, and adsorption dynamics of the protein by the material. We have developed several
unique nanoscale fluorescent spectroscopies to image the heterogeneity of protein dynamics
within hydrogels.
Maxim Dzero, Kent State University, Spins & Knots: The rise of Topology in f-orbital materials Mon. January 29th, 2018
12:45 pm-1:45 pm

Spins & Knots: The rise of Topology in f-orbital materials

Maxim Dzero

Kent State University

In my talk I will review the key recent theoretical and experimental works on a new class of topological material systems – topological Kondo insulators, which appear as a result of interplay between strong correlations and spin-orbit interactions. I will discuss the history of Kondo insulators is along with the theoretical models used to describe these heavy fermion compounds. The Fu-Kane method of topological classification of insulators is used to show that hybridization between the conduction electrons and localized f-electrons in these systems gives rise to interaction- induced topological insulating behavior.

Elshad Allahyarov, Duisburg-Essen University and CWRU, Smectic monolayer confined on a sphere: topology at the particle scale Mon. January 22nd, 2018
12:45 pm-1:45 pm

Prof. Dr. Elshad Allahyarov, 

Duisburg-Essen University, Germany, and  Physics Department  CWRU

Smectic monolayer confined on a sphere: topology at the particle scale

The impact of topology on the structure of a smectic monolayer confined to a sphere is explored by particle-resolved computer simulations of hard rods. The orientations of the particles are either free or restricted to a prescribed director field with a latitude or longitude orderings. Depending on the imprinted topology, a wealth of different states are found including equatorial smectic with isotropic poles, equatorial smectic with empty poles,


Scroll To Top