In the American economic system, competition is a critical driver of performance and innovation. The same can be said for materials physics. My group focuses on studying a variety of strongly correlated quantum systems, where the competition between charge, spin and orbital degrees of freedom can lead to novel or enhanced properties. It is this sensitivity that makes these materials useful for devices. A good device has a measured property (such as resistance or magnetization) that changes dramatically with an external stimulus (such as current, temperature or magnetic field). Competition is a valuable strategy for creating this interplay of parameters. Magnetic competition in magnetic systems, on the other hand, has often been seen as a hindrance. While it typically decreases the overall net magnetization, I will show that it can be utilized to generate novel phenomena useful for devices, such as giant negative magnetization and enhanced magnetization at small applied fields. While much research on magnetism utilizes large fields to strengthen the net magnetization, most devices will need to utilize small fields. While my group also collaborates on a wide range of other systems (such as topological insulators, delafossites and transition edge sensors), much of our focus has been to grow high-quality films and understand the interfacial interactions in magnetic and magnetoelectric layers. I will discuss our first observation of a magnetoelectric dead layer, which motivated our recent interest and successes in magnetic phase competition and then some of the interesting features we have discovered in complex oxide thin films.
The UBEC conference series addresses broad themes of BEC that cross through all types of condensates, including cold atoms, helium and hydrogen, superconductors, quasiparticle condensation, photons and lasing, and condensation in nuclear physics, astrophysics and cosmology.
The conference will begin with an evening reception Sunday, March 31, and end Friday, April 5, at 3:00 pm. Talks will begin Monday, April 1, promptly at 9:00 am. There will be a poster session on Tuesday, April 2, and conference excursions on the afternoon of Thursday, April 4. The conference banquet will be ...
Susan Fullerton, an assistant professor of chemical and petroleum engineering at the University of Pittsburgh, is one of five winners presented with the 2019 AAAS Marion Milligan Mason Awards for Women in the Chemical Sciences at a 13 December awards ceremony at the American Association for the Advancement of Science headquarters.
She and her team had created a new ion conductor with a particularly unique property: once the transistor was turned on it stayed on, and once it was turned off it stayed off in the absence of a power supply. This enables memory sticks to store information even when they are disconnected from a computer. Fullerton envisions a future where this type of switching could lead to a memory stick that operates on much lower power than those on the market today and to devices with never-before-seen properties, such as one that can be triggered to permanently destroy its data if it falls into the wrong hands.
The ability to engineer controllable atom-photon interactions is at the heart of quantum optics and quantum information processing. In this talk, I will introduce a nanophotonic platform for engineering strong atom-photon interactions on a semiconductor chip. I will first discuss an experimental demonstration of a spin-photon quantum transistor , a fundamental building block for quantum repeaters and quantum networks. The device allows a single spin trapped inside a semiconductor quantum dot to switch a single photon, and vice versa, a single photon to flip the spin. I will discuss how...
Dirac discovered that every fundamental particle must also have a distinct anti-particle which has the opposite charge. When particles and anti-particles meet, they annihilate each other releasing energy. In 1937, Ettore Majorana predicted the existence of a special class of particles where the particle and the anti-particle are identical. However, with the possible exception of neutrinos, so far there are no known fundamental particles that belong to this class. Recently, the possible realization of these exotic Majorana fermions as quasiparticle excitations in in solids has created much...
Nathaniel Rosi is included on the list of the Clarivate Analytics website that “recognizes world-class researchers selected for their exceptional research performance, demonstrated by production of multiple highly cited papers that rank in the top 1% by citations for field and year in Web of Science”. This is the third consecutive year that Dr. Rosi has been included on this list. The Highly Cited Researchers list from Clarivate Analytics identifies scientists and social scientists who have demonstrated significant influence through publication of multiple highly cited papers during the last decade.
Dr. Mikael Kuisma seeks quantitative and qualitative understanding of nanoscale quantum dynamics, such as collective excitations in functionalized noble metal nanoparticles and hot carrier generation with potential applications from microscopy to photovoltaics. He is also a developer of GPAW electronic structure program, which he further utilized to run large scale parallel models of electron dynamics in nanosystems.
Marking her ability to inspire students through novel demonstrations of complex subjects as well as her mentoring of women and underrepresented minorities, PQI member Susan Fullerton was awarded the 2018 James Pommersheim Award for Excellence in Teaching by the Department of Chemical and Petroleum Engineering.
The Pommersheim Award was established by the Department and James M. Pommersheim '70 to recognize departmental faculty in the areas of lecturing, teaching, research methodology, and research mentorship of students. Dr. Pommersheim, formerly Professor of Chemical Engineering at Bucknell University, received his bachelor’s, master’s and PhD in chemical engineering from Pitt. “Susan’s accomplishments in teaching over such a short period of time speak to the heart of the Pommersheim award. Her imaginative use of hands-on experiments and demonstrations create a tremendous amount of enthusiasm among our students and generate her impressive teaching scores to match,” noted Steven Little, department chair and professor. “Also, Susan’s presentations on the “imposter syndrome” and achieving work-life balance have generated tremendous campus interest. She has candidly shared her own experiences to help our students understand that feeling like an imposter is normal, and can drive further successes.”
A general scientific overview of the quantum mechanics and how computational quantum chemistry can be used to better engineer chemical reaction and functional materials.
Experimental research at the nanoscale continues to challenge our ability to predict the behavior of quantum systems. Advances with lithographically patterned solid-state electronic devices have enabled multiple platforms for the simulation of quantum matter. In particular, semiconductor quantum dots and superconducting qubits provide tools for studying the wealth of physics induced by nonlinearities at the single electron and single microwave-photon level, respectively, and have been separately pursued as enabling technologies for qubits. In recent years, hybrid devices that combine such historically distinct lines of research have received greater attention, whether to enable novel sensing or measurement applications, or to couple small systems of qubits together at long range (e.g. quantum transduction). I will showcase the rich behaviors and phases of quantum matter that coupled quantum dots can exhibit, including a surprising transport mechanism called cotunneling drag, signatures of Kondo physics with emergent symmetry , and non-Fermi liquid states. I will also discuss my work towards fabricating superconducting qubits on silicon-on-insulator substrates for hybrid device applications. The integration of quantum dots and superconducting resonators promises to yield new probes for studying quantum matter, and superconducting qubits are coming of age in their own right for the implementation of many-body spin models.