Publications (28)
Extreme-Scale Atomistic Simulation of Real-Temperature Magnetic Skyrmion Dynamics by Coupled Spin-Lattice Modeling
Pin Chen, Cheng-bing Chen, Hai Liu +9
Real-temperature topological magnetic dynamics in functional materials is governed by coupled lattice and spin evolution, yet remains inaccessible to predictive simulation at devic…
Incorporating Wavefront Error, Wavefront Sensing and Control, and Sensitivities into Exposure Time Calculations for Future Space Missions with the Error Budget Software (EBS)
Sarah Steiger, Pin Chen, Laurent Pueyo
A primary goal of NASA's Habitable Worlds Observatory (HWO) mission concept is to explore the Habitable Zones (HZ) of ~100 stellar systems and acquire spectra of ~25 terrestrial-ty…
Current laboratory performance of starlight suppression systems, and potential pathways to desired Habitable Worlds Observatory exoplanet science capabilities
Bertrand Mennesson, Ruslan Belikov, Emiel Por +34
We summarize the current best polychromatic (10 to 20 % bandwidth) contrast performance demonstrated in the laboratory by different starlight suppression approaches and systems des…
Spectropolarimetry as a Means to Address Cloud Composition and Habitability for a Cloudy Exoplanetary Atmosphere in the Habitable Zone
Robert A. West, Philip Dumont, Renyu Hu +3
In our solar system, the densely cloud-covered atmosphere of Venus stands out as an example of how polarimetry can be used to gain information on cloud composition and particle mea…
Simulated performance of energy-resolving detectors towards exoplanet imaging with the Habitable Worlds Observatory
Sarah Steiger, Laurent Pueyo, Emiel H. Por +5
One of the primary science goals of the Habitable Worlds Observatory (HWO) as defined by the Astro2020 decadal survey is the imaging of the first Earth-like planet around a Sun-lik…
Benchmarking GNNs for OOD Materials Property Prediction with Uncertainty Quantification
Liqin Tan, Pin Chen, Menghan Liu +3
We present MatUQ, a benchmark framework for evaluating graph neural networks (GNNs) on out-of-distribution (OOD) materials property prediction with uncertainty quantification (UQ).…
Crystal Structure Prediction by Joint Equivariant Diffusion
Rui Jiao, Wenbing Huang, Peijia Lin +4
Crystal Structure Prediction (CSP) is crucial in various scientific disciplines. While CSP can be addressed by employing currently-prevailing generative models (e.g. diffusion mode…
LUVOIR-ECLIPS closed-loop adaptive optics performance and contrast predictions
Axel Potier, Garreth Ruane, Pin Chen +8
One of the primary science goals of the Large UV/Optical/Infrared Surveyor (LUVOIR) mission concept is to detect and characterize Earth-like exoplanets orbiting nearby stars with d…
The Super-Earth Opportunity - Search for Habitable Exoplanets in the 2020s
Renyu Hu, Charles A. Beichman, David Brain +23
The recent discovery of a staggering diversity of planets beyond the Solar System has brought with it a greatly expanded search space for habitable worlds. The Kepler exoplanet sur…
Buildup of Abiotic Oxygen and Ozone in Moist Atmospheres of Temperate Terrestrial Exoplanets and its Impact on the Spectral Fingerprint in Transit Observations
Armin Kleinböhl, Karen Willacy, A. James Friedson +2
We investigate the abiotic production of oxygen and its photochemical byproduct ozone through water vapor photolysis in moist atmospheres of temperate terrestrial exoplanets. The a…
Equivariant Diffusion for Crystal Structure Prediction
Peijia Lin, Pin Chen, Rui Jiao +6
In addressing the challenge of Crystal Structure Prediction (CSP), symmetry-aware deep learning models, particularly diffusion models, have been extensively studied, which treat CS…
Searching High Temperature Superconductors with the assistance of Graph Neural Networks
Liang Gu, Yang Liu, Pin Chen +5
Predicting high temperature superconductors has long been a great challenge. A major difficulty is how to predict the transition temperature Tc of superconductors. Recently, progre…
Wavefront sensing and control in space-based coronagraph instruments using Zernike's phase-contrast method
Garreth Ruane, J. Kent Wallace, John Steeves +14
Future space telescopes with coronagraph instruments will use a wavefront sensor (WFS) to measure and correct for phase errors and stabilize the stellar intensity in high-contrast…
Ultraviolet Technology To Prepare For The Habitable Worlds Observatory
Sarah Tuttle, Mark Matsumura, David R. Ardila +22
We present here the current state of a collection of promising ultraviolet technologies in preparation for the Habitable Worlds Observatory. Working with experts representing a sig…
Early Architecture Concepts for the Habitable Worlds Observatory -- System Design, Modeling, and Analysis
Alice, Liu, Marie Levine +30
The Habitable Worlds Observatory (HWO), NASA's next flagship science mission, follows in the tradition of the Nancy Grace Roman Space Telescope and other preceding great observator…
Water, Methane, and Carbon Dioxide Present in the Dayside Spectrum of the Exoplanet HD 209458b
M. Swain, G. Tinetti, G. Vasisht +11
Using the NICMOS instrument on the Hubble Space Telescope, we have measured the dayside spectrum of HD 209458b between 1.5--2.5 microns. The emergent spectrum is dominated by featu…
Multi-epoch ultraviolet observables for breaking the radius-albedo degeneracy in directly imaged exoplanets
Suniti Sanghavi, Robert A. West, Pin Chen
Direct imaging measures how bright a planet appears in reflected starlight, but brightness alone cannot tell whether the planet is large and dark or small and bright. This radius-a…
Characterizing Earth analogs may require a moderate or high-resolution spectrograph
Jean-Baptiste Ruffio, Sarah Steiger, Corey Spohn +16
A primary goal of the Habitable Worlds Observatory (HWO) is to detect and measure the abundance of biosignature molecules, such as water (H2O) and oxygen (O2), in the atmosphere of…
Adaptive optics performance of a simulated coronagraph instrument on a large, segmented space telescope in steady state
Axel Potier, Garreth Ruane, Christopher C. Stark +9
Directly imaging Earth-like exoplanets (``exoEarths'') with a coronagraph instrument on a space telescope requires a stable wavefront with optical path differences limited to tens…
Contrast performance of an 8m off-axis, segmented space telescope equipped with an adaptive optics system
Axel Potier, Garreth Ruane, Kiarash Tajdaran +9
The Astro2020 decadal survey recommended an infrared, optical, ultra-violet (IR/O/UV) telescope with a 6~m inscribed diameter and equipped with a coronagraph instrument to di…
Thermochemistry and Photochemistry in Cooler Hydrogen Dominated Extrasolar Planets: The Case of GJ436b
Michael R Line, Gautam Vasisht, Pin Chen +2
We introduce a new thermochemical kinetics and photochemical model. We use high-temperature bidirectional reaction rates for important H, C, O and N reactions (most importantly for…
Molecular Signatures in the Near Infrared Dayside Spectrum of HD 189733b
M. R. Swain, G. Vasisht, G. Tinetti +5
We have measured the dayside spectrum of HD 189733b between 1.5 and 2.5 microns using the NICMOS instrument on the Hubble Space Telescope. The emergent spectrum contains significan…
Unraveling Antagonistic Collision-Controlled Reactivity in Energetic Molecular Perovskites with Deep Potential Molecular Dynamics
Ming-Yu Guo, Yun-Fan Yan, Pin Chen +1
The precise regulation of chemical decompositions in energetic materials, whether towards rapid ignition or stable endurance, requires atomic-scale principles governing reactivity,…
HPC-AI Coupling Methodology for Scientific Applications
Yutong Lu, Dan Huang, Pin Chen
Artificial intelligence (AI) technologies have fundamentally transformed numerical-based high-performance computing (HPC) applications with data-driven approaches and endeavored to…
Cross-Model Validation of Coronagraphic Exposure Time Calculators for the Habitable Worlds Observatory: A Report from the Exoplanet Science Yield sub-Working Group
Christopher C. Stark, Sarah Steiger, Armen Tokadjian +9
Estimating the exoplanet scientific productivity of the Habitable Worlds Observatory requires estimating science exposure times. From exoplanet yields to spectral retrievals, expos…
Spectral Domain Z-scan Technique
Xi Zeng, Pengfei Qi, Pin Chen +2
Characterizing the nonlinear optical properties of various materials plays a prerequisite role in nonlinear optics. Among different methods, the well-known Z-scan technique and the…
A ground-based near-infrared emission spectrum of the exoplanet HD 189733b
Mark R. Swain, Pieter Deroo, Caitlin A. Griffith +9
Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H2O), methane (CH4), carbon dioxide (CO2), and carbon mon…
Leveraging Large-scale Computational Database and Deep Learning for Accurate Prediction of Material Properties
Pin Chen, Jianwen Chen, Hui Yan +6
Accurately predicting the physical and chemical properties of materials remains one of the most challenging tasks in material design, and one effective strategy is to construct a r…