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It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.

Konrad Lorenz

Colloquia

Physics Conference Room, SB B326
Coffee starts at 12:00 PM and talk starts at 12:15 PM
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11
Sep '23
In-person
+ Online
UCLA
Clarice Aiello
“Quantum Biology”: How nature harnesses quantum processes
Abstract:
“Quantum Biology”: how nature harnesses quantum processes to function optimally, 
and how might we control such quantum processes to therapeutic and tech advantage

Imagine driving cell activities to treat injuries and disease simply by using tailored magnetic fields. Many relevant physiological processes, such as: the regulation of oxidative stress, proliferation, and respiration rates in cells; wound healing; ion channel functioning; and DNA repair were all demonstrated to be controlled by weak magnetic fields (with a strength on the order of that produced by your cell phone). Such macroscopic physiological responses to magnetic fields are consistent with being driven by chemical reactions that depend on the electron quantum property of spin. In the long-term, the electromagnetic fine-tuning of endogenous “quantum knobs” existing in nature could enable the development of drugs and therapeutic devices that could heal the human body — in a way that is non-invasive, remotely actuated, and easily accessible by anyone with a mobile phone. However, whereas spin-dependent chemical reactions have been unambiguously established for test-tube chemistry (bearing uncanny similarities with what physicists call “spin quantum sensing”), current research has not been able to deterministically link spin states to physiological outcomes in vivo and in real time. With novel quantum instrumentation, we are learning to control spin states within cells and tissues, having as a goal to write the “codebook” on how to deterministically alter physiology with weak magnetic fields to therapeutic and technological advantage. 

Bio
Prof. Clarice D. Aiello is a quantum engineer interested in how quantum physics informs biology at the nanoscale. She is an expert on nanosensors harnessing room-temperature quantum effects in noisy environments. Aiello received her B.S. in Physics from the Ecole Polytechnique; her M.Phil. in Physics from the University of Cambridge, Trinity College; and her Ph.D. from MIT in Electrical Engineering. She also held postdoctoral appointments in Bioengineering at Stanford, and in Chemistry at Berkeley. Two months before the pandemic, she joined UCLA, where she leads the Quantum Biology Tech (QuBiT) Lab.

 
2
Oct '23
In-person
+ Online
Rochester Institute of Technology
Mishkat Bhattacharya
Optical Tweezer Phonon Laser
Abstract:
In this talk I will describe our recent theoretical work on optomechanics with levitated nanoparticles. I will address cooling and regenerative center-of-mass motion (phonon lasing) theory in relation to the experiments in the group of our collaborator A. N. Vamivakas at the University of Rochester.

[1] S. Sharma, A. Kani and M. Bhattacharya, Phys. Rev. A 105, 043505 (2022)
[2] R. M. Pettit, W. Ge, P. Kumar, D. R. L.-Martin, J. T. Schulz, L. P. Neukirch, M. Bhattacharya and A. N. Vamivakas, Nature Photonics 13, 372 (2019) 

 
10
Oct '23
In-person
+ Online
City College, CUNY
Vinod Menon
Half-light half-matter quasiparticles: from condensation to quantum nonlinearity
Abstract:
Strong light-matter interaction results in the formation of half-light half-matter quasiparticles called polaritons that take on the properties of both its constituents. In this talk I will first introduce the concept of strong light-matter coupling in low-dimensional semiconductors in optical cavities. Following this, I will discuss the formation of Bose Einstein like condensates at room temperature using polaritons formed in organic molecules1. Approaches to create condensate lattices in such systems will also be presented. Next, I will present our recent work on polaritons in 2D materials and their potential to reach quantum nonlinearity2. I will conclude with a discussion on the potential of strong light-matter coupling to engineer magneto-optic response of 2D materials3,4.

1.    Deshmukh, P. et al. A plug-and-play molecular approach for room temperature polariton condensation. ArXiv 2304.11608 (2023).
2.    Datta, B. et al. Highly nonlinear dipolar exciton-polaritons in bilayer MoS2. Nature Communications 2022 13:1 13, 1–7 (2022).
3.    Dirnberger, F. et al. Spin-correlated exciton–polaritons in a van der Waals magnet. Nature Nanotechnology 2022 17:10 17, 1060–1064 (2022).
4.    Dirnberger, F. et al. Magneto-optics in a van der Waals magnet tuned by self-hybridized polaritons. Nature 620, 533–537 (2023).
 
 
30
Oct '23
In-person
+ Online
Oakland University
Evgeniy Khain
Intriguing dynamics in a dense cell monolayer
Abstract:
In this talk, we consider an expansion of a dense monolayer of cells: a collective multicellular phenomenon, where cells divide, grow, and maintain contacts with their neighbors. During migration, cells display complex behavior, adjusting both their division rate and their growth after division to the local mechanical environment. Experimental observations show that cells near the edge of the expanding monolayer are larger and move faster than cells deep inside the colony. To explain these observations and describe cell migration patterns, we formulate a spatio-temporal theoretical model for multicellular dynamics in terms of the cell area distribution; the model includes cell growth after division and effective pressure. Numerical simulations of the model predict both the speed of invasion and the width of the outer proliferative rim; these predictions are in a good agreement with experimental observations. Theoretical analysis yields the equation for density of cells and reveals a novel type of propagating front with compact support. The velocity of front propagation (monolayer expansion) is obtained analytically and its dependence on all the relevant parameters is determined.
13
Nov '23
In-person
+ Online
University of Maryland, College Park
Carlos Ríos Ocampo
Nonvolatile programmable photonics
20
Nov '23
In-person
+ Online
Museum of Natural History
Isabel Colman
Empirical approaches to the stellar age-rotation connection in the era of Big Data
Abstract:
Fifty years ago, astronomers discovered a relationship between stellar age and rotation: as stars grow older, they lose angular momentum and "spin down" — or, their rotation period gradually increases. Twenty years ago, the term "gyrochronology" was introduced to describe the metholodology of using a star's rotation period to determine its age. Empirical gyrochronology has to account for the peculiarities of individual stars, and has so far proved that there's no one-size-fits-all relation — but with more data, we can probe more regions of parameter space. Ten years ago, NASA's Kepler mission ended, providing the stellar astrophysics community with four-year continuous time series photometry for over 100,000 stars in one area of the sky. The data from Kepler opened up the study of gyrochronology, but also necessitated the development of new methods for rotation period detection and analysis. With data from ensuing missions K2 and TESS,  opportunities to test gyrochronology have blossomed, and the challenges of this analysis have grown more complex. In this talk, I'll cover the history and foundations of gyrochronology, the state of the field, and my work developing software for detecting and classifying stellar rotation in data from the TESS mission.
11
Dec '23
Next Event
In-person
+ Online
University of Connecticut
Bahram Javidi
Automated Disease Identification with Multidimensional Optical Imaging
This talk is accessible via Zoom or use
meeting ID 829 2687 2594 and passcode 866995 to join
Abstract:

This seminar is an overview of recent and reported research in rapid automated disease identification with low-cost field portable bio-photonics systems through the analysis of blood cells using multidimensional digital holographic systems. Statistical and/or deep learning algorithms are used to analyze the spatial and temporal characteristics of the reconstructed blood cells for automated disease identification. Recent applications of digital holography and dedicated algorithms for rapid COVID-19 detection will be presented. We present a variety of bio-photonics sensors including 3D printed thin lensless sensors using pseudo-random phase encoding. Conventional holographic systems require a stable optical table for reliable performance. Self-referencing holographic systems show much greater stability and are field portable. Experimental results are presented to illustrate the performance of these instruments in the field such as health clinics for COVID-19 detection, Sickle Cell disease detection, etc. Dedicated algorithms to inspect and classify cells such as blood cells using field portable holographic systems for automated disease identification will be presented. Recent advances in the proposed bio-photonics sensors give this approach agreat potential for success.

Bio:
Prof. Bahram Javidi is Board of Trustees Distinguished Professor at University of Connecticut. His interests are in a broad range of transformative imaging approaches using optics and photonics, and he has made seminal contributions to passive and active multidimensional imaging from nano to micro and macro scales. His recent research activities include digital holography, polarimetric 3D imaging at low light, 3D visualization and recognition of objects in photon-starved environments; automated disease identification using biophotonics with compact digital holographic sensors for use in developing countries; and optical cyber physical security. He has 35 patents some of which have been licensed by industry. He has been awarded The Optica (OSA) Emmett Leith medal (2021), Optica C. E. K. Mees Medal (2019), and Optica Joseph Fraunhofer Award / Robert M. Burley Prize (2018); The IEEE Photonics Society William Streifer Scientific Achievement Award (2019); and the European Physical Society (EPS) Prize for Applied Aspects of Quantum Electronics and Optics (2015). He was awarded the IEEE Donald G. Fink Paper Prize (2008); the John Simon Guggenheim Foundation Fellow Award (2008); the Alexander von Humboldt Foundation Prize (2007); the SPIE Technology Achievement Award (2008); and the SPIE Dennis Gabor Award (2005). He was named an IEEE Photonics Society Distinguished Lecturer in 2004 and 2005; and was the 2010 recipient of the George Washington University's Distinguished Alumni Scholar Award. He has been named Fellow of IEEE, OSA, SPIE, AIMBE, National Academy of Inventors, and Inst. of Physics. 

5
Feb '24
In-person
+ Online
Cambridge University
Luca Sapienza
Controlling light down to the single-photon level with integrated quantum photonic devices
This talk is accessible via Zoom or use
meeting ID 829 2687 2594 and passcode 866995 to join
Abstract:
Light-matter interactions allow adding functionalities to photonic on-chip devices, thus enabling developments in classical and quantum light sources, energy harvesters and sensors. These advances have been facilitated by precise control in growth and fabrication techniques that have opened new pathways to the design and realization of semiconductor devices where light emission, trapping and guidance can be efficiently controlled at the nanoscale. 
In this context, I will show the implementation of semiconductor quantum dots in nano-photonic devices that can create simultaneously bright and pure, triggered single-photon sources [1], critical for quantum information technology.  I will then present photonic geometries for controlling light propagation and brightness in broadband, scalable devices, based on plasmonic nanostructures [2]. 
Hybrid systems can allow overcoming limitations due to specific material properties and I will show how hybrid III-V/Silicon devices can be a platform for low-loss quantum light propagation [3]. I will also present a technique based on the transfer of semiconductor membranes embedding quantum emitters onto different host materials [4], for hybrid quantum photonic applications [5].
Finally, I will discuss novel photonic designs based on bio-inspired aperiodic [6] and disordered photonic crystals [7], showing efficient light confinement and optical sensing, and I will present our recent work on quantum biology, focused on the investigation of photosynthetic light harvesters on a chip.

References:
[1] L. Sapienza et al., Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission, Nature Communications 6, 7833 (2015).
[2] O.J. Trojak, S.I. Park, J.D. Song, L. Sapienza, Metallic nanorings for broadband, enhanced extraction of light from solid-state emitters, Applied Physics Letters 111, 021109 (2017).
[3] M. Davanco, J. Liu, L. Sapienza et al., Heterogeneous integration for on-chip quantum photonic circuits with single quantum dot devices, Nature Communications 8, 889 (2017).
[4] C. Haws, B. Guha, E. Perez, M. Davanco, J.D. Song, K. Srinivasan, L. Sapienza, Thermal release tape-assisted semiconductor membrane transfer process for hybrid photonic devices embedding quantum emitters, Materials for Quantum Technology 2, 025003 (2022). 
[5] C. Haws, E. Perez, M. Davanco, J.D. Song, K. Srinivasan, L. Sapienza, Broadband, efficient extraction of quantum light by a photonic device comprised of a metallic nano-ring and a gold back reflector, Applied Physics Letters 120, 081103 (2022). 
[6] O.J. Trojak, S. Gorsky, F. Sgrignuoli, F.A. Pinheiro, S.-I. Park, J.D. Song, L. Dal Negro, L. Sapienza, Cavity quantum electro-dynamics with solid-state emitters in aperiodic nano-photonic spiral devices, Applied Physics Letters 117, 124006 (2020)
[7] T. Crane, O.J. Trojak, J.P. Vasco, S. Hughes, L. Sapienza, Anderson localisation of visible light on a nanophotonic chip, ACS Photonics 4, 2274 (2017).

Short Bio:
Luca Sapienza is an Associate Professor in Quantum Engineering at the University of Cambridge (United Kingdom), where he is leading the Integrated Quantum Photonics research group,whose activities focus on the fundamental understanding of quantum optics effects on a chip, the development of quantum and nano-photonic devices integrating single-photon emitters, and the study of quantum effects in bio-molecules.
He graduated summa cum laude from the University of Padua (Italy) and obtained his PhD with highest honours from the University Paris-Diderot (France). 
He has held visiting positions at the National Institute of Standards and Technology (USA) and at the Ecole Normale Superieure de Paris (France). He is the Chair of the Semiconductor Physics group of the Institute of Physics, Editor of Materials for Quantum Technology, Fellow and Deputy Dean at Christ’s College Cambridge.
12
Feb '24
In-person
+ Online
CNRS, Institut d'Optique, Bordeaux, France
Philippe Lalanne
Nanoresonators
This talk is accessible via Zoom or use
meeting ID 829 2687 2594 and passcode 866995 to join
Abstract:
Nanoresonators play a pivotal role in enhancing various light-matter interaction phenomena. These systems are open and exhibit resonances, often referred to as quasinormal modes or QNMs, which possess complex frequencies. The imaginary component of these frequencies encodes either an exponential decay ("damping") over time or an exponential growth ("amplification") in space. The physics of   non-Hermitian systems offers a significantly more intricate landscape compared to their Hermitian counterparts; however, it is accompanied by the challenge of dealing with more intricate mathematical formulations.

Over the past decade, there has been notable advancement in the theory of electromagnetic QNMs. To the extent that there are now freely available software packages that aid in conducting modal analyses of the   interaction between light and nanoresonators. In this context, we will provide an overview of the current state of the art in electromagnetic QNMs theory, encompassing aspects like their computation, regularization, and normalization. Additionally, we will explore several  interesting applications of this theory in understanding fundamental  properties of nanoresonators that arise due to their non-Hermitian nature.

Bio-Philippe Lalanne currently works as a CNRS Research Scientist. He is an expert in nanoscale electrodynamics, with a primary focus on modeling and theory. Over the course of his career, he has introduced novel modal theories, established general principles for designing high-Q microcavities, clarified the role of plasmons in the extraordinary optical transmissions, and demonstrated the first high-NA optical metalenses using high-index nanostructures during the late 1990s. Presently, his research interest focuses on the non-Hermitian interaction of light with nanoresonators and the characteristics of disordered optical metasurfaces. From 2018 to 2022, he held the role of Director for the GDR Ondes that gathers the French community working on electromagnetic waves. He received several distinctions, including the prestigious 2022 ERC Advanced grant. He is a fellow of IOP, SPIE and OPTICA.
26
Feb '24
In-person
+ Online
Rockefeller University
Alipasha Vaziri
Towards cortex-wide volumetric recording of neuroactivity at cellular resolution
This talk is accessible via Zoom or use
meeting ID 829 2687 2594 and passcode 866995 to join
Abstract:
Understanding how sensory information is represented, processed and leads to generation of complex behavior is the major goal of systems neuroscience. However, the ability to detect and manipulate such large-scale functional circuits has been hampered by the lack of appropriate tools and methods that allow parallel and spatiotemporally specific manipulation of neuronal population activity while capturing the dynamic activity of the entire network at high spatial and temporal resolutions. A central focus of our lab is the development and application of new optics-based neurotechnologies for large-scale, high-speed, and single-cell resolution interrogation of neuroactivity across model systems. Through these, we have consistently pushed the limits on speed, volume size, and depth at which neuronal population activity can be optically recorded at cellular resolution. Amongst others have demonstrated whole-brain recording of neuroactivity at cellular resolution in small model systems as well as more recently nearsimultaneous recording from over 1 million neurons distributed across both hemispheres and different layers of the mouse cortex at cellular resolution. I will present on our efforts on neurotechnology development and how the application of some of these optical neurotechnologies could enable solving a qualitatively new range of neurobiological questions that are beyond reach of current methods. Ultimately, our aim is to uncover some of the computational principles underlying representation of sensory information at different levels, its processing across the mammalian brain, and how its interaction with internal states generates behavior.