Phys Chem/Chem Phys Seminar

Hot exciton cooling in nanocrystals quantum dots: Why exciton under confinement relax rapidly?

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Abstract: The efficiencies of devices utilizing semiconductor nanocrystals (NCs) are predominantly regulated by nonradiative processes. One key process in this regard is hot exciton cooling, wherein a highly excited electron-hole pair undergoes nonradiative relaxation to give rise to a band-edge exciton. The timescale and mechanism of this cooling process are not comprehensively understood.

Frequency combs as the route to the spectroscopic trifecta: high time resolution, high frequency resolution, and high sensitivity

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Abstract: Many consequential chemical processes take place on ultrafast timescales, including molecular vibrations and bond breaking. Measurements that follow ultrafast molecular dynamics in real time are changing our understanding of these processes. We are designing new tools to study ultrafast molecular dynamics and quantum mechanics with the sensitivity enough to study the molecules in molecular beams and the spectral resolution sufficient for vibrational and rotational resolution.

Molecular Quantum Information Science with Electron Spins

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Abstract: Quantum technologies based on molecules afford unique potential in miniaturization, spatial localization, and tunability through synthetic chemistry. Paramagnetic molecules constitute a platform for implementing quantum bits (qubits) and quantum sensors (qusors). While electron spin decoherence can potentially be leveraged in quantum sensing applications, its use is ultimately limited by spin relaxation, which effectively leaks quantum information into the environment.

More than physics, more than data: Integrated machine-learning models for chemistry

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Abstract: Machine-learning techniques are often applied to perform "end-to-end" predictions, that is to make a black-box estimate of a property of interest using only a coarse description of the corresponding inputs.
In contrast, atomic-scale modeling of matter is most useful when it allows to gather a mechanistic insight into the microscopic processes that underlie the behavior of molecules and materials. 

Nanomaterials Enable Delivery of Genetic Material Without Transgene Integration in Mature Plants

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Abstract: Genetic engineering of plants is at the core of sustainability efforts, natural product synthesis, and agricultural crop engineering. The plant cell wall is a barrier that limits the ease and throughput with which exogenous biomolecules can be delivered to plants. Current delivery methods either suffer from host range limitations, low transformation efficiencies, tissue regenerability, tissue damage, or unavoidable DNA integration into the host genome.

Cold chemistry in hot cores: exploring the early origins of chemical complexity in nascent stellar systems

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Abstract: The interstellar medium provides an enormous laboratory for the exploration of chemistry of various kinds. But it is not a laboratory that we control, and its results - while resting on processes that individually may occur very rapidly - unfold on timescales that are typically much longer than a human lifetime. Our observations of the molecular compositions of interstellar clouds and star-forming regions represent only snapshots of a process of chemical evolution that must be pieced together through various means.

Rapid Diagnostics for Infectious Diseases Using Gold Nanoparticles

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Abstract: The global COVID-19 pandemic has underscored the need for innovations in disease diagnostics.  Paper immunoassays, such as lateral flow assays, have been a critical tool for infectious diseases. These assays are low-cost, can be used in rugged environments, and possess sample-to-answer times of minutes, so they are attractive for widespread deployment for disease surveillance, quarantining, and treatment.  Biological fluids such as blood or saliva is added to the paper strip, which wicks through.