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Wednesday, Feb 7, 2024
Dr. Georgi Gary Rozenman (MIT) 

Quantum Mechanical and Optical Inspirations in Surface Gravity Water Waves: An Analogy Exploration  

 Analogies between quantum and classical systems can be found in many areas of physics, from optics and acoustics to condensed matter and particle physics. Surface gravity water waves, for example, have been shown to exhibit analogies to both quantum mechanics and optics. By exploring such analogies, we can gain new insights into the fundamental behavior of both quantum and classical systems. While the two regimes of physics operate on vastly different scales, they are related through the notion of wave-particle duality. This duality allows quantum objects, such as photons and electrons, to display both wave-like and particle-like properties, like classical systems. 

In that regard, the phase of a matter wave, governed by the Schrödinger equation, plays a crucial role in solving fundamental problems in quantum mechanics. However, it is quite difficult to measure the full wave packet (both amplitude and phase) of matter waves. In this research, we propose both theoretical and experimental study of quantum mechanical analogies with hydrodynamics, by measuring the propagation dynamics of surface gravity water waves, which, under certain circumstances, obey the Schrödinger equation. We began this research by exploring the propagation dynamics of Gaussian and Airy wave packets and successfully observed the Kennard cubic phase for the first time. We further investigated the propagation dynamics of solitons in linear potential, a problem in which the wave packets maintain their temporal shape but accelerate. Then, we explored various systems such as the Talbot effect (or Talbot carpets) and successfully showed experimentally that the Talbot effect occurs not only in the amplitude but also in the phase. In addition, we explored the Talbot effect in the nonlinear regime and observed for the first time the absence of fractional Talbot-effect, due to interference of the periodic wave packets in a nonlinear medium. Currently, we study deeper analogies between quantum mechanics and surface waves and aim to measure scattering of wave packets from an inverted oscillator potential, quantum decoherence, ballistic wave packets as well as other different time-dependent potentials and an analogy of a black holes in phase space. Furthermore, we have recently discovered that our experimental setup allows measuring and studying Bohm trajectories and quantum potentials of different wave packet types, including two/three slits and Airy slits. In addition, this approach can also lead to an experimental observation of the Wigner distribution of the wave function or the adjunct entropy. Moreover, we have recently shown that our system can emulate antireflection temporal coatings, dark focusing and diffractive focusing and guiding of waves. These experiments aim to serve as a new type of platform for different aspects of complex optical systems fundamentals as well as fundamental quantum phenomena. 

References
[1] Rozenman, Georgi Gary, et al. "Amplitude and phase of wave packets in a linear potential." Physical Review Letters 122.12 (2019): 124302.
[2] Rozenman, Georgi Gary, Lev Shemer, and Ady Arie. "Observation of accelerating solitary wavepackets." Physical Review E 101.5 (2020): 050201.
[3] Rozenman, Georgi Gary, et al. "Periodic wave trains in nonlinear media: Talbot revivals, Akhmediev breathers, and asymmetry breaking." Physical Review Letters 128.21 (2022): 214101.
[4] Rozenman, Georgi Gary, et al. "Observation of Bohm trajectories and quantum potentials of classical waves." Physica Scripta 98.4 (2023): 044004.

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Wednesday, Feb 14, 2024
No colloquium: faculty search meetings

TBA

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Wednesday, Feb 21, 2024
Naoki Yamamoto (Keio University)

Quantum statistics; parameter estimation and model selection. 

I will present some quantum algorithms that incorporate statistical methods for lowering the required number of entangling gates as well as the number of qubits, while maintaining quantum advantage to estimate target quantities. To run such parameter estimation algorithms in a realistic situation, the key to determine the estimation performance lies in the relevant choice of the statistical model. Hence I also show a method for choosing a ``good” statistical model — a quantum information criteria. 

Reference: 

H. Yano and N. Yamamoto, Quantum information criteria for model selection in quantum state estimation, J. Physics A: Math and Theoretical, 56, 405301 (2023)

K. Wada, K. Fukuchi, and N. Yamamoto, Quantum-enhanced mean value estimation via adaptive measurement, arXiv:2210.15624 (2023)

T. Tanaka, S. Uno, T. Onodera, N. Yamamoto, and Y. Suzuki, Noisy quantum amplitude estimation without noise estimation, Phys. Rev. A 105, 012411 (2022) 

Y. Suzuki, S. Uno, R. Raymond, T. Tanaka, T. Onodera, and N. Yamamoto, Quantum amplitude estimation without phase estimation, Quantum Information Processing, 19, 75 (2020)

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Wednesday, Feb 28, 2024
No colloquium: faculty search meetings

TBA

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Wednesday, Mar 6, 2024
No colloquium: March Meeting

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Wednesday, Mar 13, 2024
No colloquium: Spring break

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Wednesday, Mar 20, 2024
Ben Allen (Emmanuel College)

Nonlinear social evolution and the emergence of collective action

Organisms from microbes to humans engage in a variety of social behaviors, which affect fitness in complex, often nonlinear ways. The question of how these behaviors evolve has consequences ranging from antibiotic resistance to human origins. However, evolution with nonlinear social interactions is challenging to model mathematically, especially in heterogeneous populations with spatial, group, and/or network structure. I will present an abstract mathematical modeling framework to study these questions. This framework leads to a condition that predicts selection for social behavior, in populations with arbitrary (but fixed) structure. In this condition, nonlinear fitness effects are ascribed to collectives, and weighted by a new measure of collective relatedness. As examples, I will apply this condition to games between relatives, and to dilemmas of collective help or harm among siblings and on spatial networks. Our work provides a rigorous basis for extending the notion of "actor", in the study of social evolution, from individuals to collectives.

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Wednesday, Mar 27, 2024
Shawn Dubey (Brown University)

Training Deep 3D Convolutional Neural Networks to Extract BSM Physics Parameters Directly from HEP Data:
a Proof-of-Concept Study Using Monte Carlo Simulations

We report on a novel application of computer vision techniques to extract beyond the Standard Model (BSM) parameters directly from high energy physics (HEP) flavor data. We develop a method of transforming angular and kinematic distributions into "quasi-images" that can be used to train a convolutional neural network to perform regression tasks, similar to fitting. This contrasts with the usual classification functions performed using ML/AI in HEP. As a proof-of-concept, we train a 34-layer Residual Neural Network to regress on these images and determine the Wilson Coefficient C9 in MC (Monte Carlo) simulations of B→K*μ+μ− decays. The technique described here can be generalized and may find applicability across various HEP experiments and elsewhere.

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Wednesday, Apr 3, 2024
Desmond Fitzpatrick (IBM)

A brief history of quantum computing, thru the lens of IBM
Quantum Computing has a fascinating history, staring with Richard Feynman and others. We will quickly review some of the key historic moments in this nascent discipline, cover some of the extensive competitive landscape,  and give an update on current status, thru the lens of IBM's efforts.
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Wednesday, Apr 10, 2024
Alioscia Hamma (Universita di Napoli Federico II)

A Kind of Magic

One prize, one goal
One golden glance of what should be

We all know that entanglement is important in quantum mechanics. However, quantum behavior needs a second ingredient, commonly known as magic. Without magic, no quantum computer would be able to outperform a classical one, but not only. Quantum chaos would not ensue, and quantum thermodynamics would not be the same. Bell’s inequalities would not be violated, and black holes would always be easy to decode. Quantum many-body systems would be boring. Also all the probabilities that come from the Born rule would be trivial. Finally, without magic there would also be no gravity, according to the AdS/CFT conjecture.
All these features are captured by the notion of Stabilizer Entropy (SE), which we will introduce and explain in this talk.

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Wednesday, Apr 17, 2024
Walter Buchwald (UMass Boston)

Quantum wells to quantum dots: A new solution to an old problem

The quantum mechanical bound states associated with electrically active point defects in semiconductors, along with the experimental and mathematical techniques used to investigate them will be discussed. These concepts, when applied to the design and fabrication of a semiconductor device,  can produce three dimensional confinement of charge from a two-dimensional electron gas (2-deg). The proposed epi-layer design and self-aligned fabrication process, along with FEM simulation results, will illustrate how a combination of surface depletion effects and surface topology can modify sub-surface confining potentials in a manner superior to previous state-of-the-art.  The proposed two-terminal, Schottky/Ohmic contact device, defined by the device diameter D and the 2-deg thickness L, will then be discussed in terms of its similarities between a point defect in a semiconductor when D>>L, as well as its use as a voltage driven quantum photonic control element when D=L. The talk will conclude with how such a D=L device, when driven by a predetermined voltage/optical pulse sequence, can provide voltage modifiable reflection, absorption or emission of single photons in a fully integrated quantum photon package at near room temperatures. 

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Wednesday, Apr 24, 2024
Dionysios Christodouleas (UMass Lowell)

3-D, fluid-permeable structures for energy, sensing, and catalytic applications

This seminar will discuss the benefits of using three-dimensional fluid-permeable structures as electrodes for various applications. More specifically, the seminar will focus on presenting methods to convert inexpensive 3D fluid permeable structures (e.g., paper, fabric, wire mesh, and metallic foam) to fully functional 3D fluid-permeable electrodes for energy, sensing and catalytic applications. Our proof-of concept applications have demonstrated the unique capabilities of 3D fluid-permeable electrodes. For example, fluid-permeable platinum electrodes, when used in fluid-permeable electrochemical cells, can instantly disinfect samples that pass through them.  Paper-based and fabric-based p-type organic thermoelectric materials can be effective and compact and they could be used in wearable thermoelectric devices.

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Wednesday, May 1, 2024
Tagbo H. R. Niepa (Carnegie Mellon University)

Microbial Dynamics at Oil-Water Interfaces

Microorganisms interact with fluid interfaces in contexts relevant to health, industry and the environment. The dynamic interaction of cells with energy-rich interfaces causes them to adsorb and become trapped, eliminating a patch of the interface, and lowering the free energy of the system. However, very little is known about the effects of interfacial tension and associated stresses at fluid interfaces on cell physiology, nor about how microbes cope with the challenging environments of the air-water or oil-water interfaces. We hypothesize that cells evolving in energy-rich confinements can exhibit unique properties and survival strategies translated by phenotypic changes. Thus, we investigate the physiological responses of microbial isolates to interfacial confinements using particle tracking, pendant drop elastometry, and metabolic profiling. Here, we will discuss the responses of Pseudomonas aeruginosa and Alcanivorax borkumensis to a hexadecane-water interface. P. aeruginosa PAO1 cells form elastic films of bacteria, excreted polysaccharides, and proteins, whereas PA14 cells move actively without forming an elastic film. Similarly, mucoid strains of P. aeruginosa and A. borkumensis isolated from the lung of cystic fibrosis patient and the Deep Horizon spill, respectively, exhibit interfacial films with strong mechanical. Cell adaptation at fluid interfaces enables them to secrete appropriate biosurfactants or metabolize the interfaces. Our data support that the formation of interfacial bacterial films provides protection, in a manner akin to biofilms, enabling cells to cope with the detrimental effects of interfacial environments. The knowledge gained through these studies opens avenues to develop new technologies to mimic and manipulate the bacteria at oil-water interfaces for applications in anti-fouling and bioremediation.

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