Seminar

mK to km: How Millikelvin Physics is Reused to Explore the Earth Kilometers Below the Surface

Speaker(s): 
Dr. Robert Kleinberg
Dates: 
Monday, January 28, 2019 - 4:00pm

Robert L. Kleinberg is an Adjunct Senior Research Scholar at the Center on Global Energy Policy of the Columbia University School of International and Public Affairs.  From 1980 to 2018 he was employed by Schlumberger, attaining the rank of Schlumberger Fellow, one of about a dozen who hold this rank in a workforce of 100,000. He has served on or advised numerous government and academic committees on energy policy, and is a coauthor with Harvard faculty of a textbook on energy technology, in preparation. Dr. Kleinberg was educated at the University of California, Berkeley (B.S. Chemistry, 1971) and the University of California, San Diego (Ph.D. Physics, 1978). From 1978 to 1980 he was a post-doctoral fellow at the Exxon Corporate Research Laboratory in Linden, NJ. His work at Schlumberger focused on geophysical measurements and the characterization and delineation of unconventional fossil fuel resources. His current interests include energy technology and economics. Dr. Kleinberg has authored more than 100 academic and professional papers, holds 38 U.S. patents, and is the inventor of several geophysical instruments that have been commercialized on a worldwide basis. He is the recipient of the 2018-2019 American Physical Society Distinguished Lectureship Award on the Applications of Physics, and is a member of the National Academy of Engineering. He is also a Non-Resident Senior Fellow at the Boston University Institute for Sustainable Energy.

Electrically conductive metal-organic frameworks: insights from theory

Speaker(s): 
Christopher Hendon
Dates: 
Tuesday, February 12, 2019 - 4:00pm

Porous electrical conductors are a desirable yet evasive class of materials that would play a key role in the development of novel electrical energy storage devices. Their high surface area and electrical conductivity enable the uptake of electrolyte into their pores, forming the basis for a supercapacitive device. Metal-organic frameworks are an emerging subset of porous materials with fleeting reports of electrical conductivity suitably high for super capacitor implementation. This talk discusses our efforts to understand what gives rise to conductivity in metal-organic frameworks, and...

Understanding Molecular and Hybrid Crystals from First Principles

Speaker(s): 
Leeor Kronik
Dates: 
Thursday, January 17, 2019 - 2:30pm

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak intermolecular interactions, typically consisting of van der Waals interactions and/or hydrogen bonds. Hybrid crystals combine molecular units and covalent/ionic networks.

Both classes of crystals play an important role in many areas of science and engineering, ranging from biology and medicine to mechanics and electronics. Therefore, much effort has been dedicated to understanding their structure and properties.

Predicting the behavior of such materials from first

...

Nonlinear Dynamics and Quantum Computers

Speaker(s): 
Dr. Susan Coppersmith
Dates: 
Friday, November 30, 2018 - 12:00pm

John David Crawford was an expert in dynamical systems and bifurcation theory, which is the study of systems that are subject to strong driving. This talk will discuss why this area of research is important for quantum computation. In particular, it will be shown how concepts from nonlinear dynamics proved to be critical in the development and improvement of qubits, the fundamental building blocks of quantum computers, using quantum dots in silicon/silicon-germanium heterostructures.

Thermal Equilibrium vs. The Real World

Speaker(s): 
Dr. Susan Coppersmith
Dates: 
Thursday, November 29, 2018 - 11:00am

Most of our understanding of the properties of materials comes from the study of thermal equilibrium, which is the state reached if one leaves a system undisturbed for long enough. But for many disordered materials, “long enough” is often years or even centuries. This talk will discuss how insights from the study of nonlinear dynamics, the field to which John David Crawford made many important contributions, have enabled us to understand some striking phenomena that do not occur in thermal equilibrium and are seen in experiments.

Explore Chemical Diversity in Complex System Toward Functional Materials

Speaker(s): 
Ting Xu
Dates: 
Thursday, November 15, 2018 - 2:30pm

The scientific community has been striving for decades to generate biomimetic materials to access many of the beneficial properties seen in Nature. Significant efforts have been devoted to systems that contain a small number of variables and can be mastered without too many unknowns. However, there has been limited success in generating complex systems as seen in Nature. As the systemic complexity increases, the phase diagram becomes less manageable with many possible states and kinetic pathways. Our central hypothesis is that rational design can lead to control over system energy...

Classical to Quantum Logic and Memory with 2D crystals: Promises and Current Realities

Speaker(s): 
Dr. Debdeep Jena
Dates: 
Wednesday, November 7, 2018 - 12:00pm

Which physical properties of 2D and layered materials can we exploit for powering the next generation of devices that power all of classical information systems?  And which 2D materials are showing promise to enable the future quantum information systems, and why? I will discuss the two questions above. The first question will lead us to the quantum mechanical roots of why current state of the art transistors are slipping away ~1000x more energy than what is needed for logic operations.  And more so than logic, the bottleneck of memory devices threatens to significantly throttle increased...

A Gap Protected zero-Hall Effect State in a Semimetal with Glide Symmetry

Speaker(s): 
Dr. Nai Phuan Ong
Dates: 
Monday, February 18, 2019 - 4:00pm

Abstract: A new direction in topological quantum matter research is the exploration of the large class of nonsymmorphic metals which include glide symmetry operations in their space group (a glide gx =Mx.T is a mirror reflection Mx combined with a fractional translation T in the mirror plane). The layered material KHgSb is analogous to stacking graphene together with distinct ions in the A and B sublattices. A half-lattice translation between adjacent layers renders it nonsymmorphic. KHgSb has been predicted to feature double quantum spin Hall (QSH) surface states in addition to hourglass...

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