New Materials for Next Generation Printable Solar Cells

The Prospects for Scalable Quantum Computing with Superconducting Circuits

Dramatic progress has been made in the last decade and a half towards realizing solid-state systems for quantum information processing with superconducting quantum circuits. Artificial atoms (or qubits) based on Josephson junctions have improved their coherence times more than a million-fold, have been entangled, and used to perform simple quantum algorithms. The next challenge for the field is demonstrating quantum error correction that actually improves the lifetimes, a necessary step for building more complex systems. At Yale we have been pursuing a hardware-efficient approach for error correction, that relies on encoding information in a bosonic oscillator, the so-called “cat codes.” With this approach, we have applied real-time measurements and feedback to achieve the first extension of the lifetime of a quantum bit through error correction. For scaling, an attractive approach is the modular architecture, in which small quantum processors are networked together into a larger whole. I will present a realization of a gate between logical qubits. This is the first implementation of a teleported C-NOT gate, which is a key building block for the modular approach.

Quantum Chromodynamics in the Exascale Era with the Emergence of Quantum Computing

What would Thomas Malthus tell us in the 21st Century?: Experiences in the Water-Energy-Food Nexus from an International Development Perspective

Ongoing research focused on analyzing the synergies and tradeoffs posed by the water-energy-food nexus is presented. This covers the need for quantitative tools (e.g., data, models) to support the analysis of integrated water, energy and food systems, from a perspective relevant to the work of international development organizations: dialog with countries and increasing awareness of “nexus” thinking and planning, building regional and in-country capacity toward integrated planning and identification/evaluation of trade-offs and synergies in developing such systems, and fostering interdisciplinary expertise in principles, algorithms, and model formulations for understanding and evaluating the potential of implementing nexus approaches within a systems perspective. This research stresses the necessity of integrating areas of disciplinary expertise, the ability to identify and address shared needs of water, energy and food stakeholders, and facilitating tailored analyses over different spatial and temporal scales. Outputs and products of recent nexus work will highlight further research and development needs focused on upstream sector planning in order to identify primary opportunities and constraints to water, energy, and food system development, and also result in an improved understanding of economic and social trade-offs among competing nexus priorities, and particularly prioritization of sector investments. Four recent experiences in South Africa, China, the Middle East and Latin America are presented as examples of nexus tradeoffs offering a rationale for investment rationalization and priorities.

BIO:
Dr. Fernando Miralles-Wilhelm is a hydrologist and water resources engineer with research expertise in modeling of surface and groundwater hydrology, solute transport with physical, chemical and biological processes in aquatic ecosystems, climate-hydrology-vegetation interactions, stormwater management in urban watersheds, water-energy-food nexus and system dynamics modeling. He currently serves as Executive Director of the Cooperative Institute for Climate and Satellites (CICS) and Interim Director of ESSIC (Earth System Science Interdisciplinary Center), both at the University of Maryland (UMD), where he also holds an appointment as Professor with the Department of Atmospheric and Ocean Sciences. Before joining UMD, Dr. Miralles was a Lead Specialist at the Inter-American Development Bank (IDB), where he managed the bank's investment portfolio in water resources and climate adaptation projects for the IDB’s 26 countries served in the Latin American and the Caribbean region. He is a Fellow of the American Society of Civil Engineers (2009) and a Diplomate of the American Academy of Environmental Engineers (2002) and the American Academy of Water Resources Engineers (2008). He holds a mechanical engineering diploma from Universidad Simón Bolívar in Venezuela, a Masters degree in Engineering from the University of California-Irvine, and a Ph.D. in Civil and Environmental Engineering from the Massachusetts Institute of Technology (MIT).

What’s New in Nonlinear Optics

This talk begins with a brief overview of the history of nonlinear optics and a description of some standard nonlinear optical effects. I will then turn to a more detailed discussion of two topics of current interest. The first topic is the role played by nonlinearity in the creation of rogue waves, including oceanic rogue waves. We have performed careful studies of optical wave propagation through nonlinear materials to elucidate the role of nonlinearity in the development of extreme (rogue) events. The second topic is an overview of wave propagation effects through materials characterized by a very small value of the dielectric permittivity, that is, through epsilon-near-zero (ENZ) materials. We describe some of the unusual properties of wave propagation through such materials including the huge nonlinearities that necessarily accompany ENZ conditions.

Hosted by Howard Milchberg

New quantum transport phenomena under large electric and magnetic fields

The discovery of topological insulators and semimetals has brought into focus Berry phase effects on transport properties of quantum solids. This talk will begin with an overview of anomalous Hall effect driven by Berry phase mechanism. I will then turn to two new transport phenomena. The first is the second-order Hall effect, by which a transverse current occurs in second-order response to an external electric field. I will show that the nonlinear Hall conductivitiy in the DC or low-frequency limit can be nonzero in time-reversal-invariant and inversion-breaking materials, and is governed by the dipole moment of Berry curvature in momentum space.

The second part of this talk is on thermoelectric effect under a large magnetic field. I will show that the thermopower of semimetals and narrow-gap semiconductors can be dramatically boosted in the quantum limit. In particular, the thermopower of Dirac/Weyl semimetals increases with the field without saturation and can reach extremely high values. These theoretical results suggest an immediate pathway for achieving record-high thermopower and thermoelectric figure of merit, and compare well with a recent experiment on Pb1−xSnxSe.

How Fermi Became Fermi

Enrico Fermi was one of the most significant figures of 20th century physics, with major contributions across a wide range of subdisciplines. Fermi revolutionized 20th-century physics with his theory of beta decay and his development of quantum statistics.
David N. Schwartz, the author of the recently published biography of Fermi, “The Last Man Who Knew Everything,” will discuss the development of Fermi as a physicist; the role of nature, nurture and historical circumstance in his career; and the characteristics behind both his strengths and his weaknesses. Are great physicists born, do they make themselves, or do others make them? How does the accident of one’s birth influence a career like Fermi’s? What was it that enabled Fermi to continue to contribute to the field well beyond the age when many great physicists are content to rest on their previous achievements?
David N. Schwartz holds a Ph.D. in political science from MIT and is the author of two previous books. He has worked at the State Department Bureau of Political-Military Affairs, the Brookings Institution and Goldman Sachs. He is the son of Melvin Schwartz, who shared the 1988 Nobel Prize in physics for the discovery of the muon neutrino in 1962.

The Road to Nuclear Physics from Standard Model

At the core of nuclear physics is to make predictions for complex phenomena occurring in the hottest and densest environments in nature, to determine how ordinary matter interacts with mysterious dark matter or other new particles, and to reveal any violation of fundamental symmetries of nature using nuclear targets. To achieve an unprecedented precision in these questions, the field has gradually started to eliminate its reliance on phenomenological models, and has entered an era when the underlying interactions are set to those in the Standard Model of particle physics. Light nuclear systems can now emerge directly from quark and gluon degrees of freedom and with only quantum chromodynamics(QCD) interactions in play, using the numerical method of lattice QCD. Few-body observable, such as few-hadron interactions and scattering amplitudes, as well transition amplitudes and reaction rates, have been the focus of this vastly growing field. Once obtained from QCD, and matched to effective field theories, these determinations can advance and improve the nuclear many-body calculations of exceedingly more complex systems. This talk is a brief introduction to this program and its goals, with a great focus on a few examples that demonstrate, most clearly, the roadmap from the Standard Model to nuclear physics.

Quantum Voyages, Cosmic Journeys: Exploring Physics through the Arts

From ancient monuments to modern day films, the confluence of the arts and physics has resulted in creations that have led to a deeper understanding of nature, to friendly and enchanting ways of perceiving science in action, to giving the arts a new dimension, to technological progress…and to pure fun! In this colloquium, I will navigate through three interconnected, collaborative physics-art explorations that I am currently involved in. A popular book in the making describes two revolutions of the past century, Einstein’s relativity and quantum physics, as a dialog and a personal tale. In a class entitled Where the Arts meets Physics, we bring alive the universe and the quantum world through installation and performance – cosmic canopies housing black hole mergers, raps on radioactivity, Warhol versions of Bohr-Einstein debates, and more. Collaborations with theater and dance have led to creating Quantum Voyages, an original performance piece, where two voyagers led by the spirit of knowledge enter the microscopic realm of atomic landscapes and quantum conundrums. I will share the process behind the making and fresh footage of last month’s premier of Quantum Voyages.

Gravity and Entanglement

The AdS/CFT correspondence provides a quantum theory of gravity in which spacetime and gravitational physics emerge from an ordinary non gravitational quantum system with many degrees of freedom.

In this talk, I will explain how quantum entanglement between these degrees of freedom is crucial for the emergence of a classical spacetime, and describe progress in understanding how spacetime dynamics (gravitation) arises from the physics of quantum entanglement.

So you have a degree in Science. Now what?