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Articles 781 - 810 of 3756

Full-Text Articles in Physical Sciences and Mathematics

Charge Transport And Spin Dynamics Of Color Centers In Diamond, Damon Daw Feb 2022

Charge Transport And Spin Dynamics Of Color Centers In Diamond, Damon Daw

Dissertations, Theses, and Capstone Projects

Solid state defects in diamond are promising candidates for room temperature quantum information processors (1, 3, 5). Chief among these defects is the nitrogen vacancy center (‘NV center’ or ‘NV’). The NV has long coherence times (at 300K) and its state is easily initialized, manipulated and read out (5). However, the outstanding issue of entangling NV centers in a scalable fashion, at room temperature remains a challenge. This thesis presents experimental and theoretical work aimed at achieving this goal by developing the ‘flying qubit’ framework in (1). This method for remote entanglement utilizes a charge carrier (initialized into a definite …


Identifying, Evaluating And Applying Importance Maps For Speech, Viet Anh Trinh Feb 2022

Identifying, Evaluating And Applying Importance Maps For Speech, Viet Anh Trinh

Dissertations, Theses, and Capstone Projects

Like many machine learning systems, speech models often perform well when employed on data in the same domain as their training data. However, when the inference is on out-of-domain data, performance suffers. With a fast-growing number of applications of speech models in healthcare, education, automotive, automation, etc., it is essential to ensure that speech models can generalize to out-of-domain data, especially to noisy environments in real-world scenarios. In contrast, human listeners are quite robust to noisy environments. Thus, a thorough understanding of the differences between human listeners and speech models is urgently required to enhance speech model performance in noise. …


Usability Of Health-Related Websites By Filipino-American Adults And Nursing Informatics Experts, Kathleen Begonia Feb 2022

Usability Of Health-Related Websites By Filipino-American Adults And Nursing Informatics Experts, Kathleen Begonia

Dissertations, Theses, and Capstone Projects

Filipino-Americans are an understudied minority group with high prevalence and mortality from chronic conditions, such as cardiovascular disease and diabetes. Facing barriers to care and lack of culturally appropriate health resources, they frequently use the internet to obtain health information. It is unknown whether they perceive health-related websites to be useful or easy to use because there are no published usability studies involving this population. Using the Technology Acceptance Model as a theoretical framework, this study investigated the difference between website design ratings by experts and the perceptions of Filipino-American users to determine if usability guidelines influenced the perceived ease …


Representation Learning For Chemical Activity Predictions, Mohamed S. Ayed Feb 2022

Representation Learning For Chemical Activity Predictions, Mohamed S. Ayed

Dissertations, Theses, and Capstone Projects

Computational prediction of a phenotypic response upon the chemical perturbation on a biological system plays an important role in drug discovery and many other applications. Chemical fingerprints derived from chemical structures are a widely used feature to build machine learning models. However, the fingerprints ignore the biological context, thus, they suffer from several problems such as the activity cliff and curse of dimensionality. Fundamentally, the chemical modulation of biological activities is a multi-scale process. It is the genome-wide chemical-target interactions that modulate chemical phenotypic responses. Thus, the genome-scale chemical-target interaction profile will more directly correlate with in vitro and in …


Blockchain: Key Principles, Nadezda Chikurova Feb 2022

Blockchain: Key Principles, Nadezda Chikurova

Dissertations, Theses, and Capstone Projects

“Blockchain: Key Principles” is an interactive visual project that explains the importance of data privacy and security, decentralized computing, and open-source software in the modern digital world through the history of the underlying principles of blockchain technology. Some of these key concepts have their roots in the time before the Information Age. By explaining the history of these principles, I want to present the fact that over the past centuries, humanity has been fighting for their privacy, security, and the ability to efficiently express themselves one way or another. Blockchain technology, which was introduced to the public in 2008 through …


Emotion Recognition With Audio, Video, Eeg, And Emg: A Dataset And Baseline Approaches, Jin Chen, Tony Ro, Zhigang Zhu Jan 2022

Emotion Recognition With Audio, Video, Eeg, And Emg: A Dataset And Baseline Approaches, Jin Chen, Tony Ro, Zhigang Zhu

Publications and Research

This paper describes a new posed multimodal emotional dataset and compares human emotion classification based on four different modalities - audio, video, electromyography (EMG), and electroencephalography (EEG). The results are reported with several baseline approaches using various feature extraction techniques and machine-learning algorithms. First, we collected a dataset from 11 human subjects expressing six basic emotions and one neutral emotion. We then extracted features from each modality using principal component analysis, autoencoder, convolution network, and mel-frequency cepstral coefficient (MFCC), some unique to individual modalities. A number of baseline models have been applied to compare the classification performance in emotion recognition, …


Me2b Alliance Validation Testing Report: Consumer Perception Of Legal Policies In Digital Technology, Noreen Y. Whysel, Karina Alexanyan, Shaun Spaulting, Julia Little Jan 2022

Me2b Alliance Validation Testing Report: Consumer Perception Of Legal Policies In Digital Technology, Noreen Y. Whysel, Karina Alexanyan, Shaun Spaulting, Julia Little

Publications and Research

Our relationship with technology involves legal agreements that we either review or enter into when using a technology, namely privacy policies and terms of service or terms of use (“TOS/TOU”). We initiated this research to understand if providing a formal rating of the legal policies (privacy policies and TOS/TOUs) would be valuable to consumers (or Me-s). From our early qualitative discussions, we noticed that people were unclear on whether these policies were legally binding contracts or not. Thus, a secondary objective emerged to quantitatively explore whether people knew who these policies protected (if anyone), and if the policies were perceived …


A Call For The Library Community To Deploy Best Practices Toward A Database For Biocultural Knowledge Relating To Climate Change, Martha B. Lerski Jan 2022

A Call For The Library Community To Deploy Best Practices Toward A Database For Biocultural Knowledge Relating To Climate Change, Martha B. Lerski

Publications and Research

Abstract

Purpose – In this paper, a call to the library and information science community to support documentation and conservation of cultural and biocultural heritage has been presented.

Design/methodology/approach – Based in existing Literature, this proposal is generative and descriptive— rather than prescriptive—regarding precisely how libraries should collaborate to employ technical and ethical best practices to provide access to vital data, research and cultural narratives relating to climate.

Findings – COVID-19 and climate destruction signal urgent global challenges. Library best practices are positioned to respond to climate change. Literature indicates how libraries preserve, share and cross-link cultural and scientific knowledge. …


Evolution Of Microscopic Heterogeneity And Dynamics In Choline Chloride-Based Deep Eutectic Solvents, Stephanie Spittle, Derrick Poe, Brain Doherty, Charles Kolodziej, Luke Heroux, Md Ashraful Haque, Henry Squire, Tyler Cosby, Yong Zhang, Carla Fraenza, Sahana Bhattacharyya, Madhusudan Tyagi, Jing Peng, Ramez A. Elgammal, Thomas Zawodzinski, Mark Tuckerman, Steve Greenbaum, Burcu Gurkan, Clemens Burda, Mark Dadmun, Edward J. Maginn, Joshua Sangoro Jan 2022

Evolution Of Microscopic Heterogeneity And Dynamics In Choline Chloride-Based Deep Eutectic Solvents, Stephanie Spittle, Derrick Poe, Brain Doherty, Charles Kolodziej, Luke Heroux, Md Ashraful Haque, Henry Squire, Tyler Cosby, Yong Zhang, Carla Fraenza, Sahana Bhattacharyya, Madhusudan Tyagi, Jing Peng, Ramez A. Elgammal, Thomas Zawodzinski, Mark Tuckerman, Steve Greenbaum, Burcu Gurkan, Clemens Burda, Mark Dadmun, Edward J. Maginn, Joshua Sangoro

Publications and Research

Deep eutectic solvents (DESs) are an emerging class of non-aqueous solvents that are potentially scalable, easy to prepare and functionalize for many applications ranging from biomass processing to energy storage technologies. Predictive understanding of the fundamental correlations between local structure and macroscopic properties is needed to exploit the large design space and tunability of DESs for specific applications. Here, we employ a range of computational and experimental techniques that span length-scales from molecular to macroscopic and timescales from picoseconds to seconds to study the evolution of structure and dynamics in model DESs, namely Glyceline and Ethaline, starting from the parent …


Eclipse, Osgi, And The Java Model, Raffi Khatchadourian Jan 2022

Eclipse, Osgi, And The Java Model, Raffi Khatchadourian

Open Educational Resources

No abstract provided.


Abstract Syntax Trees (Asts) And The Visitor Pattern, Raffi Khatchadourian Jan 2022

Abstract Syntax Trees (Asts) And The Visitor Pattern, Raffi Khatchadourian

Open Educational Resources

No abstract provided.


Biomedical Applications Of Lanthanide Nanomaterials, For Imaging, Sensing And Therapy, Qize Zhang, Stephen O'Brien, Jan Grimm Jan 2022

Biomedical Applications Of Lanthanide Nanomaterials, For Imaging, Sensing And Therapy, Qize Zhang, Stephen O'Brien, Jan Grimm

Publications and Research

The application of nanomaterials made of rare earth elements within biomedical sciences continues to make significant progress. The rare earth elements, also called the lanthanides, play an essential role in modern life through materials and electronics. As we learn more about their utility, function, and underlying physics, we can contemplate extending their applications to biomedicine. This particularly applies to diagnosis and radiation therapy due to their relatively unique features, such as an ultra-wide Stokes shift in the luminescence, variable magnetism and potentially tunable properties, due to the library of lanthanides available and their multivalent oxidation state chemistry. The ability to …


The Naming Of Homo Bodoensis By Roksandic And Colleagues Does Not Resolve Issues Surrounding Middle Pleistocene Human Evolution, Eric Delson, Chris Stringer Jan 2022

The Naming Of Homo Bodoensis By Roksandic And Colleagues Does Not Resolve Issues Surrounding Middle Pleistocene Human Evolution, Eric Delson, Chris Stringer

Publications and Research

Roksandic et al. (2022) proposed the new species name Homo bodoensis as a replacement name for Homo rhodesiensis Woodward, 1921, because they felt it was poorly and variably defined and was linked to sociopolitical baggage. However, the International Code of Zoological Nomenclature includes regulations on how and when such name changes are allowed, and Roksandic et al.'s arguments meet none of these requirements. It is not permitted to change a name solely because of variable (or erroneous) later use once it has been originally defined correctly, nor can a name be modified because it is offensive to one or more …


Stoichiometry Question Sets, Myungshim Kang Jan 2022

Stoichiometry Question Sets, Myungshim Kang

Open Educational Resources

This is a question pool for general chemistry. This consists of question sets, each of which contains variations of questions for topics, including the mole, molar mass, balancing chemical equations, and quantitative relationships in chemical reactions.


2d N = (0, 1) Gauge Theories And Spin(7) Orientifolds, Sebastían Franco, Alessandro Mininno, Ángel M. Uranga, Xingyang Yu Jan 2022

2d N = (0, 1) Gauge Theories And Spin(7) Orientifolds, Sebastían Franco, Alessandro Mininno, Ángel M. Uranga, Xingyang Yu

Publications and Research

We initiate the geometric engineering of 2d N = (0, 1) gauge theories on D1-branes probing singularities. To do so, we introduce a new class of backgrounds obtained as quotients of Calabi-Yau 4-folds by a combination of an anti-holomorphic involution leading to a Spin(7) cone and worldsheet parity. We refer to such constructions as Spin(7) orientifolds. Spin(7) orientifolds explicitly realize the perspective on 2d N = (0, 1) theories as real slices of N = (0, 2) ones. Remarkably, this projection is geometrically realized as Joyce’s construction of Spin(7) manifolds via quotients of Calabi-Yau 4-folds by antiholomorphic …


Extractable Entanglement From A Euclidean Hourglass, Takanori Anegawa, Norihiro Iizuka, Daniel Kabat Jan 2022

Extractable Entanglement From A Euclidean Hourglass, Takanori Anegawa, Norihiro Iizuka, Daniel Kabat

Publications and Research

We previously proposed that entanglement across a planar surface can be obtained from the partition function on a Euclidean hourglass geometry. Here we extend the prescription to spherical entangling surfaces in conformal field theory. We use the prescription to evaluate log terms in the entropy of a conformal field theory in two dimensions, a conformally coupled scalar in four dimensions, and a Maxwell field in four dimensions. For Maxwell we reproduce the extractable entropy obtained by Soni and Trivedi. We take this as evidence that the hourglass prescription provides a Euclidean technique for evaluating extractable entropy in quantum field theory.


Exploratory Programming In The Arts And Humanities [Book Review], Kelly Hammond Jan 2022

Exploratory Programming In The Arts And Humanities [Book Review], Kelly Hammond

Publications and Research

Exploratory Programming is a testament to what open-access can mean, especially in an e-learning environment. Used in full, it is a free course (that relies on free and open software) from a gifted MIT professor whose pedagogy is clear in structure and tone. He scaffolds, promotes predictive thinking, lauds collaborative learning, and urges readers to do not just to read. Used in part, it can be equally powerful.


Quark And Gluon Entanglement In The Proton On The Light Cone At Intermediate X, Adrian Dumitru, Eric Kolbusz Jan 2022

Quark And Gluon Entanglement In The Proton On The Light Cone At Intermediate X, Adrian Dumitru, Eric Kolbusz

Publications and Research

In QCD with $N_c$ colors the antisymmetric valence quark color space singlet state $\sim \epsilon_{i_1\cdots i_{N_c}} |i_1,\cdots, i_{N_c}\rangle$ of the proton corresponds to the reduced density matrix $\rho_{ij}=(1/N_c) \delta_{ij}$ for a single color degree of freedom. Its degenerate spectrum of eigenvalues, $\lambda_i=1/N_c$, the purity $\tr \rho^2 = 1/N_c$, and the von Neumann entropy $S_\mathrm{vN}=\log(N_c)$ all indicate maximal entanglement of color. On the other hand, for $N_c\to\infty$ the spatial wave function of the proton factorizes into valence quark wave functions determined by a mean field [E. Witten, Nucl. Phys. B160, 57 (1979)] where there is no entanglement of spatial degrees of …


Spin(7) Orientifolds And 2d N = (0, 1) Triality, Sebastían Franco, Alessandro Mininno, Ángel M. Uranga, Xingyang Yu Jan 2022

Spin(7) Orientifolds And 2d N = (0, 1) Triality, Sebastían Franco, Alessandro Mininno, Ángel M. Uranga, Xingyang Yu

Publications and Research

We present a new, geometric perspective on the recently proposed triality of 2d N = (0, 1) gauge theories, based on its engineering in terms of D1-branes probing Spin(7) orientifolds. In this context, triality translates into the fact that multiple gauge theories correspond to the same underlying orientifold. We show how Spin(7) orientifolds based on a particular involution, which we call the universal involution, give rise to precisely the original version of N = (0, 1) triality. Interestingly, our work also shows that the space of possibilities is significantly richer. Indeed, general Spin(7) orientifolds extend triality to theories that can …


Landslide Inventory Dataset Post Hurricane Stan (2005), Lake Atitlan Region, Guatemala, Elia Axinia Machado, Yuri Gorokhovich, Mahta Ghahremani Jan 2022

Landslide Inventory Dataset Post Hurricane Stan (2005), Lake Atitlan Region, Guatemala, Elia Axinia Machado, Yuri Gorokhovich, Mahta Ghahremani

Publications and Research

Landslides are a global hazard of devastating impacts resulting in thousands of fatalities every year, substantial economic losses, and long-term economic disruption. Examining the frequency and distribution of landslides is important to better understand their associated factors and to identify where future landslides may occur. The dataset described in this article consists of landslides digitized as polygons using high resolution aerial photography collected after Hurricane Stan (October 2005), which caused severe damages in Central America. In Guatemala, the total economic impact of Hurricane Stan has been estimated at US$983 Million dollars, with 719,000 ha of land lost due to flooding, …


Bft2: A General Class Of 2d N = (0, 2) Theories, 3-Manifolds And Toric Geometry, Sebastían Franco, Xingyang Yu Jan 2022

Bft2: A General Class Of 2d N = (0, 2) Theories, 3-Manifolds And Toric Geometry, Sebastían Franco, Xingyang Yu

Publications and Research

We introduce and initiate the study of a general class of 2d N = (0, 2) quiver gauge theories, defined in terms of certain 2-dimensional CW complexes on oriented 3- manifolds. We refer to this class of theories as BFT2’s. They are natural generalizations of Brane Brick Models, which capture the gauge theories on D1-branes probing toric Calabi-Yau 4-folds. The dynamics and triality of the gauge theories translate into simple transformations of the underlying CW complexes. We introduce various combinatorial tools for analyzing these theories and investigate their connections to toric Calabi-Yau manifolds, which arise as their …


A Framework For Near-Real Time Monitoring Of Diversity Patterns Based On Indirect Remote Sensing, With An Application In The Brazilian Atlantic Rainforest, Andrea Paz, Thiago S. Silva, Ana C. Carnaval Jan 2022

A Framework For Near-Real Time Monitoring Of Diversity Patterns Based On Indirect Remote Sensing, With An Application In The Brazilian Atlantic Rainforest, Andrea Paz, Thiago S. Silva, Ana C. Carnaval

Publications and Research

Monitoring biodiversity change is key to effective conservation policy. While it is difficult to establish in situ biodiversity monitoring programs at broad geographical scales, remote sensing advances allow for near-real time Earth observations that may help with this goal. We combine periodical and freely available remote sensing information describing temperature and precipitation with curated biological information from several groups of animals and plants in the Brazilian Atlantic rainforest to design an indirect remote sensing framework that monitors potential loss and gain of biodiversity in near-real time. Using data from biological collections and information from repeated field inventories, we demonstrate that …


Magnetoexcitons In Phosphorene Monolayers, Bilayers, And Van Der Waals Heterostructures, Roman Ya. Kezerashvili, Anastasia Spiridonova, Andrew Dublin Jan 2022

Magnetoexcitons In Phosphorene Monolayers, Bilayers, And Van Der Waals Heterostructures, Roman Ya. Kezerashvili, Anastasia Spiridonova, Andrew Dublin

Publications and Research

We study direct and indirect excitons in Rydberg states in phosphorene monolayers, bilayers, and van der Waals (vdW) heterostructure in an external magnetic field within the framework of the effective-mass approximation. The magnetic field is applied perpendicular to the monolayer or heterostructure and is varied between 0 and 60 T. Binding energies of magnetoexcitons are calculated by numerical integration of the Schrödinger equation using the Rytova-Keldysh potential for direct magnetoexcitons and both the Rytova-Keldysh and Coulomb potentials for indirect magnetoexcitons. The latter aids in the understanding of the role of screening in phosphorene. We report the magnetic field energy contribution …


Fano 3-Folds, Reflexive Polytopes And Brane Brick Models, Sebastían Franco, Rak-Kyeong Seong Jan 2022

Fano 3-Folds, Reflexive Polytopes And Brane Brick Models, Sebastían Franco, Rak-Kyeong Seong

Publications and Research

Reflexive polytopes in n dimensions have attracted much attention both in mathematics and theoretical physics due to their connection to Fano n-folds and mirror symmetry. This work focuses on the 18 regular reflexive polytopes corresponding to smooth Fano 3-folds. For the first time, we show that all 18 regular reflexive polytopes have corresponding 2d (0, 2) gauge theories realized by brane brick models. These 2d gauge theories can be considered as the worldvolume theories of D1-branes probing the toric Calabi-Yau 4-singularities whose toric diagrams are given by the associated regular reflexive polytopes. The generators of the mesonic moduli …


Characterizing Changes In Extreme Ozone Levels Under 2050s Climate Conditions: An Extreme-Value Analysis In California, Bradley Wilson, Mariah Pope, Jeremy R. Porter, Edward Kearns, Evelyn Shu, Mark Bauer, Neil Freeman, Mike Amodeo, David Melecio-Vazquez, Ho Hsieh, Maggie Tarasovitch Jan 2022

Characterizing Changes In Extreme Ozone Levels Under 2050s Climate Conditions: An Extreme-Value Analysis In California, Bradley Wilson, Mariah Pope, Jeremy R. Porter, Edward Kearns, Evelyn Shu, Mark Bauer, Neil Freeman, Mike Amodeo, David Melecio-Vazquez, Ho Hsieh, Maggie Tarasovitch

Publications and Research

Ground-level ozone has a well established climate penalty associated with changing meteorological conditions under future climate change, but most existing research focuses exclusively on ozone-temperature relationships defined at specific locations. Using an extreme-value theory approach, we model relationships between temperature, humidity, and vapor pressure deficit and maximum daily 8 h ozone concentrations (MDA8) across California using a combination of ozone station network data and Community Multiscale Air Quality Modeling System (CMAQ) model output from 2008 to 2017. We use a spatial regression with time varying bias coefficients to fuse station observations and modeled output into a spatially explicit gridded ozone …


Strain‑Induced Quantum Hall Phenomena Of Excitons In Graphene, Oleg L. Berman, Roman Ya. Kezerashvili, Yurii E. Lozovik, Klaus G. Ziegler Jan 2022

Strain‑Induced Quantum Hall Phenomena Of Excitons In Graphene, Oleg L. Berman, Roman Ya. Kezerashvili, Yurii E. Lozovik, Klaus G. Ziegler

Publications and Research

We study direct and indirect pseudomagnetoexcitons, formed by an electron and a hole in the layers of gapped graphene under strain‑induced gauge pseudomagnetic field. Since the train‑induced pseudomagnetic field acts on electrons and holes the same way, it occurs that the properties of single pseudomagnetoexcitons, their collective effects and phase diagram are cardinally different from those of magnetoexcitons in a real magnetic field. We have derived wave functions and energy spectrum of direct in a monolayer and indirect pseudomagnetoexcitons in a double layer of gapped graphene. The quantum Hall effect for direct and indirect excitons was predicted in the monolayers …


Perspectives On Determinism In Quantum Mechanics: Born, Bohm, And The 'Quantal Newtonian' Laws, Viraht Sahni Jan 2022

Perspectives On Determinism In Quantum Mechanics: Born, Bohm, And The 'Quantal Newtonian' Laws, Viraht Sahni

Publications and Research

Quantum mechanics has a deterministic Schrödinger equation for the wave function. The Göttingen-Copenhagen statistical interpretation is based on the Born Rule that interprets the wave function as a ‘probability amplitude’. A precept of this interpretation is the lack of determinism in quantum mechanics. The Bohm interpretation is that the wave function is a source of a field experienced by the electrons, thereby attributing determinism to quantum theory. In this paper we present a new perspective on such determinism. The ideas are based on the equations of motion or ‘Quantal Newtonian’ Laws obeyed by each electron. These Laws, derived from the …


Mathematics For Liberal Arts (Ma301), Lecture Notes, Lyubomir I. Boyadzhiev Jan 2022

Mathematics For Liberal Arts (Ma301), Lecture Notes, Lyubomir I. Boyadzhiev

Open Educational Resources

These lecture notes are designed to provide the students majoring in the liberal arts with an understanding and appreciation of mathematics as a lively, interesting, and surprisingly rich human activity with many fascinating applications. The text, emphasizing strongly intuitive thinking and visualization, is a collection of topics chosen to show the open-minded readers that:

  • The connection between the mathematics presented in the course and down-to-earth, concrete real-life problems is transparent and immediate.
  • Modern mathematical discoveries do not have to be the exclusive province of professional mathematicians.
  • There is an important aesthetic component in mathematics, and just as in art and …


Observation Of Localized Magnetic Plasmon Skyrmions, Zi-Lan Deng, Tan Shi, Alex Krasnok, Xiangping Li, Andrea Alù Jan 2022

Observation Of Localized Magnetic Plasmon Skyrmions, Zi-Lan Deng, Tan Shi, Alex Krasnok, Xiangping Li, Andrea Alù

Advanced Science Research Center

Optical skyrmions have recently been constructed by tailoring vectorial near-field distributions through the interference of multiple surface plasmon polaritons, offering promising features for advanced information processing, transport and storage. Here, we provide experimental demonstration of electromagnetic skyrmions based on magnetic localized spoof plasmons (LSP) showing large topological robustness against continuous deformations, without stringent external interference conditions. By directly measuring the spatial profile of all three vectorial magnetic fields, we reveal multiple ��-twist target skyrmion configurations mapped to multi-resonant near-equidistant LSP eigenmodes. The real-space skyrmion topology is robust against deformations of the meta-structure, demonstrating flexible skyrmionic textures for arbitrary shapes. The …


Planar Chiral Metasurfaces With Maximal And Tunable Chiroptical Response Driven By Bound States In The Continuum, Tan Shi, Zi-Lan Deng, Guangzhou Geng, Xianzhi Zeng, Yixuan Zeng, Guangwei Hu, Adam Overvig, Junjie Li, Cheng-Wei Qiu, Andrea Alù, Yuri S. Kivshar, Xiangping Li Jan 2022

Planar Chiral Metasurfaces With Maximal And Tunable Chiroptical Response Driven By Bound States In The Continuum, Tan Shi, Zi-Lan Deng, Guangzhou Geng, Xianzhi Zeng, Yixuan Zeng, Guangwei Hu, Adam Overvig, Junjie Li, Cheng-Wei Qiu, Andrea Alù, Yuri S. Kivshar, Xiangping Li

Advanced Science Research Center

Optical metasurfaces with high quality factors (Q-factors) of chiral resonances can boost substantially light-matter interaction for various applications of chiral response in ultrathin, active, and nonlinear metadevices. However, current approaches lack the flexibility to enhance and tune the chirality and Q-factor simultaneously. Here, we suggest a design of chiral metasurface supporting bound state in the continuum (BIC) and demonstrate experimentally chiroptical responses with ultra-high Q-factors and near-perfect circular dichroism (CD = 0.93) at optical frequencies. We employ the symmetry-reduced metaatoms with high birefringence supporting winding elliptical eigenstate polarizations with opposite helicity. It provides a convenient way for achieving the maximal …