Molecular Nano-Architectures for Energy and Electronics

Yu Zhong
Thursday, January 13, 2022 - 10:30am

A Pitt Chem Seminar

Abstract: Since the discovery of conducting polymers, organic materials have promised great applications in energy conversion, electronics, and chemical sensing. Synthetic chemistry has been rapidly advancing the development of organic materials with desired properties and functions. At the core of the research is understanding the structure-property relationships and developing new chemical structures and synthetic methods. In this talk, I will present several design principles of functional organic materials based on the concept of...

Embarking on a Thermal Journey in Low Dimensions with a 21st century thermometer: Graphene Nonlocal Noise

Jonah Waissman
Monday, January 10, 2022 - 3:30pm

A Pitt/CMU Colloquium 

Abstract: Low-dimensional materials, such as 2D monolayers, 1D nanowires, and 0D quantum dots and molecules, are rich with many-body quantum phenomena. The reduced dimensionality, strong interactions, and topological effects lead to new emergent degrees of freedom of fundamental interest and promise for future applications, such as energy-efficient computation and quantum information. Thermal transport, which is sensitive to all energy-carrying degrees of freedom and their interactions, provides a...

Spin physics in graphene nanostructures

Thomas Frederiksen
Friday, December 10, 2021 - 11:30am

A GNR Qubit MURI Seminar

11:30a-11:35a General discussion and introductions
11:35a-11:40a Intro to MURI team and concept (Levy)
11:40a-11:50a Blitz talk #1 Davis Welakuh Mbangheku
11:50a-12:00p Blitz talk #2 Erin Sheridan
12:00p-12:50p Thomas Frederiksen talk
12:50p-1:00p Discussion and wrap up

Title: Spin physics in graphene nanostructures


Atomic-scale control over size, shape, and composition of graphenenanostructures has become a reality through on-surface synthesiswhereby...

Local to Meso-scale Order in Electronic Ceramics Characterized by Aberration-Corrected Scanning Transmission Electron Microscopy

Elizabeth Dickey
Friday, December 3, 2021 - 12:15pm

A CMU MSE Seminar

Abstract: The ability to design the composition and microstructure of electronic ceramics for emerging technological applications requires sophisticated characterization techniques that can provide quantitative information about local structure and chemistry. Such structure quantification is particularly important to the fundamental understanding of properties in many important non-linear dielectrics, where chemical heterogeneities associated with dopants or intrinsic lattice defects give rise to local inhomogeneities in charge, strain and...

Structural Inhomogeneity in Oxide Superconductors

Martin Greven
Wednesday, December 8, 2021 - 4:00pm

Abstract: Superconductivity has been a major research topic for more than a century, yet in many important materials this macroscopic quantum phenomenon remains poorly understood. We have uncovered that superconductivity emerges in an unusual, yet remarkably universal manner upon cooling in three well-known families of complex oxides – strontium titanate, strontium ruthenate, and the cuprates – for which the origin of superconductivity is thought to differ [1]. This breakthrough was enabled by nonlinear magnetic response measurements, an innovative experimental approach...

Quantum Advantage in Optical Laser Communications using NISQ-era Quantum Processors

Kaushik P. Seshadreesan
Friday, December 3, 2021 - 11:00am

A PQI Seminar

Abstract: Optical laser communication forms a cornerstone of modern-day data communications. In the quantum-limited regime of lasercom, where the received optical signal power is small, e.g., in deep-space communications, pre-detection quantum domain collective processing of blocks of received signal pulses corresponding to communication codewords can provide enhanced communication capacity. We present a novel quantum receiver design methodology based on a quantum belief propagation algorithm that attains such enhancement. I will discuss the...

Topological Spintronics

Nitin Samarth
Monday, November 22, 2021 - 3:30pm

A Pitt/CMU Physics Colloquium

Abstract: The past decade has witnessed an explosion of activity in exploring the properties of topological quantum materials whose band structure has interesting features arising from the nexus of topology, spin-orbit coupling, and fundamental symmetries. A key characteristic of the band structure in many of these materials is the ‘spin-momentum correlation’ in helical Dirac states. This leads to the notion of ‘topological spintronics’ devices that seek to exploit efficient spin-charge interconversion for low power, non-...

Continuous Single-Shot Detection of Quasiparticle Trapping

Eli Levenson-Falk
Tuesday, November 16, 2021 - 3:00pm

A Pitt Physics seminar


Abstract: Superconducting quantum circuits are plagued by nonequilibrium populations of quasiparticle excitations. These quasiparticles can cause relaxation and spurious excitation of qubit states, producing errors in a quantum algorithm, and can cause correlated errors that are particularly difficult to address with error...

Strong Interactions, Color Confinement, and Strings

Igor Klebanov
Monday, October 25, 2021 - 3:30pm

A Pitt/CMU Colloquium 

Abstract: In the 1950s and 60s many strongly interacting particles were discovered. String theory was originally invented to describe them, but Quantum Chromodynamics (QCD) emerged as the precise theory of the strong nuclear force. A quarter century later it was understood that string theory and certain gauge theories akin to QCD are different descriptions of the same physics. I will review the relations between gauge theories and strings. Their formation in QCD is a manifestation of the confinement of colored quarks and gluons. While...

Nonvolatile light modulation in optoelectronic nanodevices

Carlos Ríos Ocampo
Wednesday, October 20, 2021 - 12:00pm

A Pitt ECE Seminar

Abstract: The active control of phase and amplitude of light enables programmable nanophotonic devices, enabling optical technologies such as switching networks, beam steering, sensing, computing, and quantum processing with photons. Phase modulation is often achieved with carrier injection or depletion in semiconductors, thermo-optic effect, and mechanical actuators, while the amplitude is modulated using electro-absorption in semiconductors. In both types of modulators, the state and information they carry are lost once the power is turned off....