Logo
Sign up to receive notifications:

The most important thing we can do is inspire young minds and to advance the kind of science, math and technology education that will help youngsters take us to the next phase of space travel.

John Glenn

Colloquia

Physics Conference Room, SB B326
Coffee starts at 12:00 PM and talk starts at 12:15 PM
iCal feed Help icon
iCalendar (*.ics extension) is a popular file format used to distribute calendar information between different applications over the internet.

Once you click the iCal feed link with the right button, copy the link URL and paste it into any calendar app that takes iCal feeds (Google Calendar, Outlook, etc).

Left click on a single event downloads the *.ics file with selected event, but it will not allow calendar apps to update automatically their calendar with other or upcoming events.


How to use feed with:
Google Calendar
Microsoft Outlook
Mozilla Thunderbird
29
Jan '24
In-person
+ Online
Boston College
Benedetta Flebus
A solid-state platform for cooperative quantum phenomena
Abstract:
The dissipation resulting from the coupling of a system with its environment is commonly viewed as a foe for quantum technologies. Nonetheless, recent developments at light-matter interfaces have shown that correlated dissipation can be harnessed into novel dynamical states of matter and entanglement in many-body quantum systems. In this talk, I will discuss how we have recently capitalized on this knowledge from quantum optics to set the stage for the — yet uncharted — exploration of cooperative quantum phenomena in quantum hybrid solid-state platforms [1]. I will first introduce a comprehensive formalism for the quantum many-body dynamics of an ensemble of solid-state spin defects interacting via the magnetic field fluctuations of a common solid-state reservoir, and then show that dissipative correlations can play a relevant role in a realistic experimental setup. Finally, I will discuss how our findings offer a pathway to novel quantum sensing modalities and schemes for realizing long-range qubit-qubit coupling.

[1] X. Li, J. Marino, D. Chang and B. Flebus,  arXiv:2309.08991 (2023)
5
Feb '24
In-person
+ Online
Cambridge University
Luca Sapienza
Controlling light down to the single-photon level with integrated quantum photonic devices
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.
14
Feb '24
In-person
+ Online
Weizmann Institute of Science
David Tannor
Exploring New Formulations of Classical and Quantum Mechanics
Abstract:
This talk has three parts. The first part is an introduction to Hamilton’s two monumental papers from 1834-1835, which introduced the Hamilton-Jacobi equation, Hamilton’s equations of motion and the principle of least action [1]. These three formulations of classical mechanics became the three forerunners of quantum mechanics; but ironically none of them is what Hamilton was looking for -- he was looking for a “magical” function, the principal function from which the entire trajectory history can be obtained just by differentiation (no integration) [2]. In the second part of the talk I argue that Hamilton’s principal function is almost certainly more magical than even Hamilton realized. Astonishingly, all of the above formulations of classical mechanics can be derived just from assuming that is additive, with no input of physics [3]. The third part of the talk will present a new formulation of quantum mechanics in which the
Hamilton-Jacobi equation is extended to complex-valued trajectories [4], allowing the treatment of classically allowed processes, classically forbidden process and arbitrary time-dependent external fields within a single, coherent framework. The approach is illustrated for barrier tunneling, wavepacket revivals, nonadiabatic dynamics, optical excitation using shaped laser pulses and high harmonic generation with strong field attosecond pulses [5].

1. W. R. Hamilton, On a General Method in Dynamics, Philosophical Transactions, Part 2, p. 247 (1834); ibid., Second Essay on a General Method in Dynamics, Part 1, p. 95 (1835).
2. M. Nakane and C. G. Fraser, The Early History of Hamilton-Jacobi Dynamics 1834-1837, Centaurus 44, 161 (2002); C. Lanczos, The Variational Principles of Mechanics (Oxford, 1949)
3. D. J. Tannor, New derivation of Hamilton’s three formulations of classical mechanics (preprint); ibid, Duality of the Principle of Least Action: A New Formulation of Classical Mechanics, arXiv:2109.09094 (2021).
4. Y. Goldfarb, I. Degani and D. J. Tannor, Bohmian mechanics with complex action: A new trajectory based formulation of quantum mechanics, J. Chem. Phys. 125, 231103 (2006); J. Schiff, Y. Goldfarb and D. J. Tannor, Path integral derivations of complex trajectory methods, Phys. Rev. A 83, 012104 (2011); N. Zamstein and D. J. Tannor, Overcoming the root search problem in complex quantum trajectory calculations, J. Chem. Phys. 140, 041105(2014).
5. N. Zamstein and D. J. Tannor, Non-adiabatic molecular dynamics with complex quantum trajectories. I. The adiabatic representation, J. Chem. Phys. 137, 22A518 (2012); W. Koch and D. J. Tannor, Wavepacket revivals via complex trajectory propagation, Chem. Phys. Lett. 683, 306 (2017); W. Koch and D. J. Tannor, A three-step model of high harmonic generation using complex classical trajectories, Annals of Physics, 427, 168288 (2021).
4
Mar '24
In-person
+ Online
City College, CUNY
Alexander Khanikaev
Topological photonics and polaritonics
Abstract:
The past decade has witnessed a dramatic shift in our understanding of quantum and classical wave phenomena triggered by the discovery of topological states of matter. Unprecedented new phenomena, such as dissipationless and reflectionless transport, enabled by topology have sparked a tremendous interest in this subject and research activity across different fields, from condensed matter to acoustics and photonics. In this talk, focusing primarily on the works of my group, I will give a brief introduction to topological photonics and a historical perspective on how this field evolved leading to the latest advances and new exotic states of light and matter.  Starting with analogies between classical wave systems and quantum condensed matter systems, I will show how topologically robust spin-polarized transport can be realized in photonic systems. Next, I will discuss the topic of higher-order photonic topological insulators and peculiarities specific to such systems that are not present in their condensed matter counterparts. Finally, I will show that by mixing topological photons with excitations and quasiparticles of solid-state systems one obtains a powerful platform for controlling light-matter interactions. In particular, an emergence of topological polaritons – half-light half-matter excitations – in Van der Waals materials, including valleys polarized topological exciton-polaritons in transition metal dichalcogenides and topological phonon-polaritons in hexagonal boron nitride (hBN), will be discussed.
11
Mar '24
Online
CNRS, Institut d'Optique, Bordeaux, France
Philippe Lalanne
Nanoresonators
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.
18
Mar '24
In-person
+ Online
Université de Montréal
William Witczak-Krempa
The Fate of Entanglement
Abstract:
Quantum entanglement is a fundamentally non-local correlation between particles. In its simplest realisation, a measurement on one particle is affected by a prior measurement on its partner, irrespective of their separation. For multiple particles, purely collective types of entanglement exist but their detection, even theoretically, remains an outstanding open question. Here, we show that all forms of multi-party entanglement entirely disappear during the typical evolution of a system as it is heats up, evolves in time, or as its parts become separated. These results follow from the nature of the entanglement-free continent in the space of physical states, and hold in great generality. We illustrate these phenomena with a frustrated molecular quantum magnet in and out of equilibrium. In contrast, if the particles are fermions, such as electrons, another notion of entanglement exists that precludes entanglement-free regions, and thus protects quantum correlations. These findings provide fundamental knowledge about the structure of entanglement in quantum matter and architectures, paving the way for its manipulation.

[Parez, Witczak-Krempa, arXiv:2402.06677]
25
Mar '24
In-person
+ Online
Courant Institute, New York University
Alex Mogilner
Physics of mitotic spindle assembly
Abstract:
Mitotic spindle is a remarkable molecular machine that self-assembles prior to cell division in order to segregate chromosomes. The spindle looks simple: two centrosomes organize two microtubule asters, and the microtubules connect to the chromosomes. However, there is an enormous molecular and mechanical complexity behind this machine, and the physics behind its self-organization became clear only recently. I will first discuss a many-body mechanics approach to the spindle that helped to understand the earliest stage of the spindle assembly, and then will show how stochastic tug-of-war models shed light on error correction process in mitosis.
1
Apr '24
In-person
+ Online
Stony Brook University
Amy Marschilok
Electrochemical energy storage (batteries): A keystone for a clean energy future
Abstract:
Energy is a necessity which touches every aspect of our modern lives. Access to clean, affordable energy directly scales with quality of human life. While the electrical grid and the automobile have been recognized as two of the greatest engineering achievements of the 20th century (NAP 2003), electric power and transportation remain the two largest U.S. sources of greenhouse gas emissions in the 21st century (EPA 2022). The central role of electrochemical energy storage systems (batteries) as a keystone for a sustainable energy future will be described in this presentation, including advances in beyond lithium-ion battery systems. The demands of different applications and the opportunities presented by different battery chemistry, materials science, and engineering solutions will be discussed. The criticality of in-situ and operando approaches to understand battery function under application relevant use cases will be highlighted.
 

Bio:
Amy Marschilok is a Professor in the Department of Chemistry at Stony Brook University, where she is an Adjunct Faculty in the Departments of Materials Science and Engineering and Chemical and Molecular Engineering and Co-Director of the Institute of Energy: Sustainability, Environment, and Equity (I:SEE).  Dr. Marschilok holds a Joint Appointment at Brookhaven National Laboratory, where she serves as Energy Storage Division Manager and Energy Systems Division Manager in the Interdisciplinary Science Department.  She also serves as Director of the Center for Mesoscale Transport Properties (http://www.stonybrook.edu/commcms/m2m/index.html), an Energy Frontier Research Center funded by the U.S. Department of Energy. Dr. Marschilok was previously employed as a Senior Scientist in the Medical Battery Research and Development group at Greatbatch Inc., where she was recognized as a Visionary of the Year. She was also honored with the Woman of Distinction Award, Education Category Recipient from GSWNY and the Western New York YWCA Leadership Award, Professional Service Category.  She was an inaugural cohort member of the Oppenheimer Science and Energy Leadership Program, and is currently part of cohort 6 of the Battelle Laboratory Operations and Supervisor Academy. Current service activities include membership on the Board of Directors for the Society of Electroanalytical Chemistry and the New York Battery and Energy Storage Technology Consortium. Her current research centers on electrochemistry-based and -coupled characterization approaches; materials and electrode concepts for high power, high energy density, extended life batteries; and operando investigations of energy storage materials and systems.
15
Apr '24
In-person
+ Online
Queens College of CUNY
Euclides Almeida
Extreme nonlinear metamaterials
Abstract:
Nanophotonics holds promise for realizing compact devices that can address global challenges such as energy-efficient communication, space exploration, and clean energy sources. At the nanoscale, the electromagnetic energy of light is squeezed to dimensions much smaller than the wavelength, leading to enhanced interaction with matter. In particular, nonlinear optical interactions greatly benefit from this extreme light confinement. Several subwavelength nonlinear materials, also known as nonlinear metasurfaces, have been shown to capitalize on the enhanced near-field. The possibility of integrating these materials into devices will enable various applications, including imaging, holography, and high-speed photonic communications. Despite these promises, efficiency and tunability issues can hinder integrating nonlinear metasurfaces into compact devices. In this talk, I will discuss our recent results in developing efficient, broadband, and widely tunable nonlinear metasurfaces based on novel hybrid lightmatter states. The talk will focus on two systems: 1) hybrid states of gold and graphene plasmons and 2) hybrid states of excitons in two-dimensional semiconductors and plasmons in metals. On the one hand, hybrid states enable broadband operation and improve efficiency. On the other hand, employing two-dimensional materials as a platform provides wide tunability due to the unique properties of these materials. Pushing the limits of nonlinear light-matter interaction will lead to a new class of ultrathin electro-optical metadevices that can simultaneously generate and control light.
6
May '24
In-person
+ Online
Rockefeller University
Alipasha Vaziri
Towards cortex-wide volumetric recording of neuroactivity at cellular resolution
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.