About

Cong Su is an Assistant Professor in Materials Science and Applied Physics at Yale University, affiliated with the Energy Science Institute and the Center for Materials Innovation. His research interests include the growth and characterization of two-dimensional (2D) quantum materials, specifically hexagonal boron nitride (hBN) and doped hBN, as well as isotopically purified hBN. His work involves solution growth techniques and the study of 2D materials' properties, which are crucial for advancing nanoelectronic and quantum device applications. Cong Su's background includes a focus on materials science and applied physics, contributing to the development of novel 2D material synthesis methods and their integration into electronic systems.

Research topics

• Chemistry
• Materials science
• Nanotechnology
• Physics
• Condensed matter physics
• Crystallography
• Optoelectronics
• Optics
• Inorganic chemistry
• Combinatorial chemistry
• Computational chemistry
• Stereochemistry
• Organic chemistry
• Electrical engineering
• Chemical physics
• Quantum mechanics
• Molecular physics

Selected publications

• Counterfactual Fairness with Imperfect Causal Graphs

  Proceedings of the AAAI Conference on Artificial Intelligence · 2026-03-14

  articleOpen access1st authorCorresponding

  Fairness-aware machine learning aims to build predictive models that comply with fairness requirements, particularly concerning sensitive attributes such as race, gender, and age. Among causality-based fairness notions, counterfactual fairness is widely adopted for its individual-level guarantees, requiring that an individual’s predicted outcome remains unchanged in a counterfactual world where its sensitive attribute is altered. However, existing methods critically assume that the true causal graph is fully known, which is rarely the case in practice. Moreover, counterfactual fairness suffers from inherent identifiability limitations, as counterfactual quantities cannot always be uniquely estimated from observational data, especially under incomplete causal knowledge. To address these challenges, we propose a principled framework (CF-ICG) for counterfactual fairness under imperfectly known causal graphs, e.g., Completed Partially Directed Acyclic Graphs (CPDAGs). We first introduce a criterion to determine the identifiability, and bound the counterfactual quantities under CPDAGs. Building upon this, we develop an efficient local algorithm that avoids the exhaustive enumeration of all DAGs, ensuring robustness against worst-case fairness violations. Experimental results on synthetic and real-world datasets demonstrate the practical effectiveness and theoretical soundness of CF-ICG.

  PublisherDOI

• Solid-phase Chalcogenization for the Synthesis of High-Quality Transition-Metal Dichalcogenide Monolayers

  Journal of the American Chemical Society · 2026-04-15

  articleSenior authorCorresponding

  Transition-metal dichalcogenide (TMD) monolayers exhibit unique electronic, photonic, and quantum phenomena, yet their material quality remains constrained by defects and thickness inhomogeneity during chemical vapor deposition. Here, we identify the limitations of the common metal trioxide precursors: high volatility that induces stochastic vapor-phase nucleation and multilayer growth, and liberated oxygen-species-mediated chemical etchants that degrade lattice integrity. We demonstrate that an acid-mediated one-step modification, dissolving trioxides in hydrochloric acid, fundamentally redirects the precursor chemistry toward nonvolatile and substrate-anchored dioxide phase. This enforces a spatially confined solid-phase chalcogenization (SPC), minimizing the vapor-phase species and thereby suppressing dechalcogenization and vertical growth. The resulting uniform monolayers, synthesized as isolated triangular flakes or continuous films, achieve state-of-the-art low defect densities: 1.87 × 1012 cm–2 for MoS2 and 1.26 × 1012 cm–2 for WSe2. Our work establishes SPC as a simple and unified mechanistic framework to drive TMD synthesis toward the intrinsic structural limits.

  PublisherDOI

• Circulating inflammatory cytokines and risk of aortic stenosis: A Mendelian randomization analysis

  Cytokine · 2025-02-21 · 1 citations

  articleOpen access

  BACKGROUND: Observational studies have consistently reported positive associations between inflammatory biomarkers and the risk of developing aortic stenosis (AS). However, it is crucial to acknowledge that conventional observational studies are prone to various forms of bias, including reverse causation and residual confounding. To delve deeper into unraveling the potential causal relationship between inflammatory biomarkers and aortic stenosis, we conducted a comprehensive two-sample Mendelian randomization (MR) analysis. METHODS: In order to explore the causal effect of exposure to various circulating cytokines on the risk of developing AS, we carefully selected AS datasets as the exposures from the summary statistics of the genome-wide association study (GWAS) conducted by FinnGen. The dataset consisted of a sample size of 3283 for AS cases and 210,463 for controls. To estimate the MR analysis, we primarily adopted the inverse variance weighted (IVW) method. Additionally, we employed complementary methods, including Weighted Median, MR Egger, Weighted Mode, and Simple Mode, to analyze the causal associations comprehensively. In order to assess the presence of heterogeneity, we utilized Cochran's Q statistic and MR-Egger regression. To ensure the robustness and consistency of our findings, we conducted a leave-one-out analysis. RESULT: We observed a positive association between interleukin-18 (IL-18) levels and AS (odds ratio [OR] per standard deviation [SD] = 1.080; 95 % confidence interval [CI] 1.024 to 1.139), as well as between interferon-gamma levels (IFN-γ) and AS (OR per SD = 1.157; 95 % CI 1.028 to 1.302). Conversely, we found an inverse association between interleukin-13 (IL-13) levels and AS (OR per SD = 0.942; 95 % CI 0.890 to 0.997), as well as between interleukin-5 (IL-5) levels and AS (OR per SD = 0.892; 95 % CI 0.804 to 0.990). CONCLUSION: Our research enhances the current understanding of the role of specific inflammatory biomarker pathways in aortic stenosis. Nevertheless, further validation is required to assess the viability of targeting these cytokines through pharmacological or lifestyle interventions as potential treatments for aortic stenosis.

  PublisherDOI

• Advances in atomic resolution secondary electron imaging

  The European Physical Journal Applied Physics · 2025-01-01

  articleOpen access

  We have developed an efficient detector of secondary electrons (SEs) for a high-performance scanning transmission electron microscope (STEM) and tested it on several materials. Using the detector at 60 keV, we resolved the nearest neighbor atoms separated by 0.142 nm in SE images of graphene, and detected single-atom substitutions in graphene and monolayer MoS 2 . We imaged single heavy atoms on an amorphous carbon thin film, and the surface structure of gold nanoparticles supported on a thin film as well as on a bulk substrate. Other application examples shown in this paper include SE imaging combined with 4D STEM, simultaneous SE and electron energy loss spectroscopy (EELS) imaging, and simultaneous imaging of entrance and exit sides of a sample using two separate SE detectors. The results point to an exciting future for atomic-resolution SE imaging.

  PublisherOA PDFDOI

• Associations of angiopoietin-like protein 7 with coronary collateral circulation and prognosis of patients with severe coronary artery stenosis

  Frontiers in Cardiovascular Medicine · 2025-10-10

  articleOpen access

  Background Angiogenesis and coronary collateral circulation (CCC) formation promote cardiac repair following severe coronary stenosis (SCS) or myocardial infarction (MI). Angiopoietin-like protein 7 (ANGPTL7) is a secreted protein associated with angiogenesis, but its role in CCC formation remains unclear. Objective The aim of this study was to investigate the role of ANGPTL7 in angiogenesis and evaluate the predictive value of serum ANGPTL7 in CCC formation and the prognosis of patients with SCS. Materials and methods The RNA sequencing was performed on myocardial tissues of mice to analyze the alterations of angiogenesis-related genes after MI. 100 patients with angiographically proven SCS and 36 controls were enrolled and retrospectively followed up. Serum ANGPTL7 was measured by enzyme-linked immunosorbent assays (ELISA). Human umbilical vein endothelial cells (HUVECs) and exogenous human recombinant ANGPTL7 protein were applied in assays including CCK-8, scratch, tube formation, cell immunofluorescence and western blot to demonstrate the proangiogenic effect of ANGPTL7. Gene Set Enrichment Analysis (GSEA) was used to perform KEGG pathway enrichment analysis on downstream mechanisms by which ANGPTL7 promoted angiogenesis. Results The transcriptional level of Angptl7 was upregulated in ischemic myocardial tissues of MI mice, and its serum levels increased in both mice post-MI and patients with SCS. Spearman correlation analysis indicated that serum ANGPTL7 levels were positively correlated to CCC grades ( r = 0.518, P < 0.001). Kaplan–Meier curves showed a higher serum ANGPTL7 was associated with a lower incidence of major adverse cardiovascular events (MACE) in patients with SCS (Log-rank test, P = 0.002). Cox proportional hazards regression analyses showed that serum ANGPTL7 level was remained a protective factor after adjusting for different covariates. Time-dependent receiver-operating characteristics (ROC) curves further explored the prognostic value of ANGPTL7, with the area under the curve (AUC) of 0.77 at 1 year, 0.70 at 2 years and 0.85 at 3 years. Additionally, ANGPTL7 enhanced endothelial cell proliferation, migration and capillary-like structure formation, indicating a proangiogenic effect in vitro . Conclusion ANGPTL7 serves as a predictive biomarker for CCC levels and the prognosis of patients with SCS, which probably attributed to its proangiogenic properties.

  PublisherOA PDFDOI

• Multi-dimensional Causality Fairness Learning

  IEEE Transactions on Knowledge and Data Engineering · 2025-01-01

  article1st authorCorresponding
  PublisherDOI

• Direct Observation of Massless Excitons and Linear Exciton Dispersion

  ArXiv.org · 2025-02-27

  preprintOpen access

  Excitons -- elementary excitations formed by bound electron-hole pairs -- govern the optical properties and excited-state dynamics of materials. In two-dimensions (2D), excitons are theoretically predicted to have a linear energy-momentum relation with a non-analytic discontinuity in the long wavelength limit, mimicking the dispersion of a photon. This results in an exciton that behaves like a massless particle, despite the fact that it is a composite boson composed of massive constituents. However, experimental observation of massless excitons has remained elusive. In this work, we unambiguously experimentally observe the predicted linear exciton dispersion in freestanding monolayer hexagonal boron nitride (hBN) using momentum-resolved electron energy-loss spectroscopy. The experimental result is in excellent agreement with our theoretical prediction based on ab initio many-body perturbation theory. Additionally, we identify the lowest dipole-allowed transition in monolayer hBN to be at 6.6 eV, illuminating a long-standing debate about the band gap of monolayer hBN. These findings provide critical insights into 2D excitonic physics and open new avenues for exciton-mediated superconductivity, Bose-Einstein condensation, and high-efficiency optoelectronic applications.

  PublisherOA PDFDOI

• A Study on the Effects of Embodied and Cognitive Interventions on Adolescents’ Flow Experience and Cognitive Patterns

  Behavioral Sciences · 2025-06-03 · 4 citations

  articleOpen access

  This study investigates the effects of embodied (breathing exercises) and cognitive interventions on adolescents’ flow experience and cognition patterns. Using a mixed-methods design, 303 vocational high school students were assigned to three groups: Embodied Task Group (N = 108), Cognitive Task Group (N = 100), and Mental Health Course Group (N = 95). Experiment 1 employed a 3×2 Multivariate Analysis of Covariance (MANCOVA) design to compare flow experience dimensions, while Experiment 2 used Epistemic Network Analysis (ENA) to analyze diary entries. Results showed that the Embodied Task Group outperformed the Cognitive Task Group in “Unambiguous Feedback” (ηp2 = 0.01, a small effect) and had higher “Transformation of Time” (ηp2 = 0.01, a small effect) than the Mental Health Course Group. ENA revealed that the Embodied Group developed stronger body-environment interaction patterns, shifting cognition pattern from psychological evaluations to dynamic bodily processes over time. Conversely, the Cognitive Task Group maintained event-focused cognition with weaker mind–body integration. Findings highlight breathing exercises’ potential to enhance flow experience through embodied awareness and multisensory processing, offering practical implications for mental health education by promoting embodied learning tasks to foster flow experience.

  PublisherOA PDFDOI

• A cancer-targeted glutathione-gated probe for self-sufficient ST/CDT combination therapy and FRET-based miRNA imaging

  Microchimica Acta · 2024-06-29 · 3 citations

  article1st authorCorresponding
  PublisherDOI

• The rise of semi-metal electronics

  Nature Reviews Electrical Engineering · 2024-08-01 · 26 citations

  article
  PublisherDOI

Frequent coauthors

• Alex Zettl

  Kavli Energy NanoScience Institute

  79 shared

• Jing Kong

  Beijing Aerospace Flight Control Center

  31 shared

• Salman Kahn

  Lawrence Berkeley National Laboratory

  31 shared

• Ju Li

  28 shared

• Congyi Cheng

  Chinese Academy of Medical Sciences & Peking Union Medical College

  27 shared

• Junlin Teng

  Peking University

  27 shared

• Jianwei Miao

  California NanoSystems Institute

  26 shared

• Huixia Lu

  Shandong University

  21 shared

Labs

• Atom E Group at Yale UniversityPI

Awards & honors

• Del Favero Prize (2020)
• Heising-Simons Fellowship (2019)
• Wellington and Irene Loh Fund Fellowship (2014)
• Alpha Nu Sigma (2014)