Jim Chelikowsky, University of Texas at Austin
Monday, February 19, 2018 - 10:30am
Cohon University Center, Wright Room

Advances in atomic force microscopy (AFM) have made it possible to achieve unprecedented images of covalent bonds, in some cases even to resolve the bond order in polycyclic aromatics. However, fundamental questions remain about interpreting the images and modeling the AFM tip. For example, the bright spots in non-contact AFM images can have a close correspondence to the atomic structure of a given specimen, but there can be contrast changes with tip height that cannot be interpreted directly by atomic positions. While the nature of the tip can be crucial in understanding the details of the image, the atomic structure of the tip is often unknown. This situation is compounded by the difficulty in simulating AFM images. In order to perform computational studies of AFM, one must determine the interatomic forces as a function of the tip height on a fine grid above the specimen.

I will present an efficient first-principles method [1] for simulating noncontact atomic force microscopy (nc-AFM) images using a “frozen density” embedding theory. Frozen density embedding theory enables one to efficiently compute the tip–sample interaction by considering a sample as a frozen external field. This method reduces the extensive computational load of first-principles AFM simulations by avoiding consideration of the entire tip–sample system and focusing on the tip alone. I will demonstrate that our simulation with frozen density embedding theory accurately reproduces full density functional theory simulations of freestanding hydrocarbon molecules while the computational time is significantly reduced. Our method also captures the...

Quantum Phenomena in Two-Dimensional Materials Driven by Atomic Scale Modifications
The extreme surface sensitivity of two-dimensional (2D) materials provides an unprecedented opportunity to engineer the physical properties of these materials via changes to their surroundings, including a substrate, adsorbates, defects, etc. In particular, the decoration of the 2Dmaterial with adatoms can be utilized to tailor material properties and induce novel quantum phenomena. In this context, first I will discuss the case of 2D semiconducting transition metal dichalcogenides (TMDs), wherein new electronic phenomena such as tunable ...
Talk location: Wean 7316 Spring 2018 Seminar
Jyoti Katoch
 Ohio State University
Student Coffee Hour
PQI is holding a coffee hour for our student and postdoc members. Our veteran poster award winners will talk about tricks and ways to prepare an award winner poster. Light refreshments will be served. If you want to be the next poster award winner at PQI2018 come and join us!
Talk location: Thaw Hall B-04 Spring 2018 Coffee Hour Student
Amy Carlson and more..
Duquesne University and TBA
AVS Western Pennsylvania Chapter Student Poster Session & Lab Tour
The AVS Western Pennsylvania Chapter invites you to attend their meeting that will have a guest speaker and student poster session, as well as a tour of the Claire and John Bertucci Nanotechnology Laboratory and Eden Hall Foundation Cleanroom. There will be multiple $200 student awards based on their poster presentations. The Guest Speaker is Sudarshan Narayanan who is a Vitro Glass R&D Engineer. The subject for the talk is “ Large Area Thin Film ...
Talk location: Claire and John Bertucci Nanotechnology Laboratory Spring 2018 Lab Tour poster
Sudarshan Narayanan
Vitro Glass
Exploiting Orbital Angular Momenta and Nonlinear Frequency Conversion in Plasmonic Devices
Surface plasmons (SPs) are evanescent waves generated through the collective oscillations of electrons at a metal/dielectric interface under optical excitation. Due to the strong light-electron coupling and near-field nature, surface plasmons offer: (1) the opportunity for sub-wavelength spatial confinement of optical waves is enabled; and (2) giant local field enhancement of optical waves is permitted. These unique attributes lead to the long-envisaged optical circuits, and allowed breakthroughs in the generally termed “plasmonics” [1]. For example, ...
Talk location: Allen Hall 321 Spring 2018 Seminar Plasmonics Nonlinear Frequency
Chen-Bin (Robin) Huang
Institute of Photonics Technologies, National Tsing Hua University
Women in Data Science Conference
Women in Data Science (WiDS) is an international conference primarily located in Stanford, CA with 80+ satellite conferences across every continent except Antarctica. In 2017, over 75,000 people attended the conference in person and via the livestream and Facebook Live. The purpose of WiDS is to inspire and educate data scientists worldwide, regardless of gender, and support women in the field; the conference features exclusively female speakers from academia and industry. Schedule Friday, March 9, ...
Talk location: Cohon University Center Spring 2018 Conference
Marlene Behrmann, Maria Mori Brooks, Amelia Haviland, Kathryn Roeder, Manuela Veloso
Carnegie Mellon University, University of Pittsburgh
Machine learning approaches to entangled quantum states
Artificial neural networks play a prominent role in the rapidly growing field of machine learning and are recently introduced to quantum many-body systems. This talk will focus on using a machine-learning model, the restricted Boltzmann machine (RBM) to describe entangled quantum states. Both short- and long-range coupled RBM will be discussed. For a short-range RBM, the associated quantum state satisfies an entanglement area law, regardless of spatial dimensions. I will present our recently constructed exact ...
Talk location: Allen Hall 321 Spring 2018 Seminar
Xiaopeng Li
Fudan University, Shanghai
Workshop on Electron Probe MicroAnalysis
This workshop sponsored by PINSE/NFCF, JEOL and Three Rivers Microscopy Society (3RMS). Workshop will provide an introduction to the world of electron microprobe and also cover some more advanced applications such as low keV analysis and effects of contamination. Some of these topics are also of interest to EDS users. This workshop is for anyone, and we welcome those who have zero knowledge of EPMA but might be interested in applications to your own research. ...
Talk location: Benedum Hall Spring 2018 Workshop Electron microscopy
Vern Robertson, Peter McSwiggen
Three Rivers Microscopy Society
Kenneth Burch (Boston College)
Talk location: CMU 2018 Seminar
Kenneth Burch
Boston College
Manuel Houzet (CEA - Grenoble Alpes University)
Talk location: 321 Allen Hall 2018 Seminar
Manuel Houzet
CEA - Grenoble Alpes University
Soft Chemistry Routes to Complex Semiconductors: Ternary Pnictide and Dichalcogenide Nanocrystals
Talk location: Chevron 150 Spring 2018 Seminar Semiconductors Dichalcogenide
Javier Vela
Iowa State University
Coupling superconducting qubits and mechanics: A path to quantum communication?
Superconducting qubits offer excellent prospects for manipulating quantum information, with good qubit lifetimes, high fidelity single- and two-qubit gates, and straightforward scalability (admittedly with multi-dimensional interconnect challenges). One interesting route for experimental development is the exploration of hybrid systems, i.e. coupling superconducting qubits to other systems. I will report on our group's efforts to develop approaches that will allow interfacing superconducting qubits in a quantum-coherent fashion to mechanical resonators and to optomechanical devices. The longer-term ...
Talk location: Thaw Hall 102 Spring 2018 Colloquium
Andrew Cleland
Institute for Molecular Engineering / University of Chicago
Alexander Balatsky (University of Connecticut, Los Alamos )
Alexander Balatsky (University of Connecticut, Los Alamos )
Talk location: Allen Hall 321 Spring 2018 Seminar
Alexander Balatsky
University of Connecticut, Los Alamos
The annual PQI signature event will cover a wide range of topics in quantum science and engineering by featuring prominent invited keynote lecturers and highlighting the current research of PQI members. All talks are colloquium-style and accessible to a broad audience.
Talk location: University Club 123 University Place PQI Event
Multiple speakers
Quantum Technology International Conference (QTech) 2018
The growing ability to manipulate quantum systems is paving the way for a second quantum revolution and a number of initiatives worldwide have been formed to foster quantum technologies. These exciting novel applications are exploiting specific quantum properties which are not accessible with classical resources such as superposition and entanglement of individual quantum systems. The objectives of the QTech conference is to present the latest developments of quantum technologies in the domains of quantum communication, ...
Talk location: Paris Spring 2018 Conference
Eleni Diamanti, Akira Furusawa
University Pierre and Marie Curie, University of Tokyo
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