About

Swastik Kar is an Associate Professor in the Department of Physics at Northeastern University College of Engineering. His research focuses on materials and nanotechnology, with notable contributions in the development of ultrasensitive ion detection devices, color-sensing technology, and ion-doped two-dimensional nanomaterials. He has been awarded multiple patents for innovations such as devices for color identification, carbon nanoribbons fabrication, and ultrasensitive ion detectors using carbon nanotubes or graphene. Professor Kar has received recognition through various research awards, including the FY24 TIER 1 Interdisciplinary Research Seed Grants and the FY21 TIER 1 Award, supporting his interdisciplinary research projects. His work has also led to startup success, with his startup Guardion winning a NASA Science Mission Directorate Challenge and earning a gold medal at the 2017 MassChallenge. His research contributions are characterized by a focus on nanomaterials and their applications in sensing technologies, advancing the field of materials science and nanotechnology.

Research topics

• Computer Science
• Materials science
• Nanotechnology
• Physics
• Optoelectronics
• Engineering physics
• Composite material
• Chemical engineering
• Condensed matter physics

Selected publications

• Conductivity scaling of the anomalous Hall effect in the altermagnetic semiconductor α-MnTe

  arXiv (Cornell University) · 2026-02-27

  preprintOpen access

  α-MnTe is a prototypical altermagnet exhibiting a strong anomalous Hall effect (AHE), despite having a nearly vanishing magnetization. Lately, sample-to-sample variations of the amplitude of the AHE have raised concerns of a possible defect related origin, especially in thin films. Here, we study the AHE in α-MnTe films grown on SrF2 that have the crystal structure and m'm'm magnetic point group symmetry expected for bulk. By studying the scaling of the AHE with conductivity for those films and previously reported measurements in the literature, we find that sample-to-sample variations are well explained by a scaling law consistent with a hopping origin. Importantly, a comparison with other magnetic semiconductors reveals the colossal amplitude of the AHE of α-MnTe compared to its measured spontaneous magnetization from magnetometry and polarized neutron reflectivity. Our findings address the important fundamental question of the origin of the AHE of α-MnTe and further demonstrate the potential of altermagnets as promising spintronic materials.

  PublisherDOI

• Recent Trends in Two‐Dimensional Transition Metal‐Tellurides and Their Applications

  Small · 2026-01-08 · 2 citations

  article

  Transition metal tellurides (TMT) form an exciting family of chalcogenides that offer a wide range of functionalities and tunability. Within this class of materials, two-dimensional (2D) TMTs are significantly more chemically stable compared to their analogous chalcogenides, e.g., 2D sulphides and selenides, making them attractive both for fundamental research and applications. This Review attempts to capture recent advances in 2D TMTs. The initial section provides an overview of potential properties offered by these low-dimensional materials. We then discuss recent and some of the most advanced synthesis techniques for producing 2D TMT at a large scale for industrial applications. We highlight how thickness-dependent magnetic modifications, strain-induced property-tuning and temperature impact both fabrication as well as properties of 2D TMTs. Focusing on these tunable physicochemical properties, a range of devices and functionalities are then presented. Properties influenced by long-range ordering such as ferromagnetism and/or superconductivity and propositions for overcoming fundamental and application challenges are discussed. The final section of the article describes advanced device application of these tunable properties.

  PublisherDOI

• Conductivity scaling of the anomalous Hall effect in the altermagnetic semiconductor α-MnTe

  ArXiv.org · 2026-02-27

  articleOpen access

  α-MnTe is a prototypical altermagnet exhibiting a strong anomalous Hall effect (AHE), despite having a nearly vanishing magnetization. Lately, sample-to-sample variations of the amplitude of the AHE have raised concerns of a possible defect related origin, especially in thin films. Here, we study the AHE in α-MnTe films grown on SrF2 that have the crystal structure and m'm'm magnetic point group symmetry expected for bulk. By studying the scaling of the AHE with conductivity for those films and previously reported measurements in the literature, we find that sample-to-sample variations are well explained by a scaling law consistent with a hopping origin. Importantly, a comparison with other magnetic semiconductors reveals the colossal amplitude of the AHE of α-MnTe compared to its measured spontaneous magnetization from magnetometry and polarized neutron reflectivity. Our findings address the important fundamental question of the origin of the AHE of α-MnTe and further demonstrate the potential of altermagnets as promising spintronic materials.

  PublisherOA PDF

• Advanced Characterization of the Spatial Variation of Moiré Heterostructures and Moiré Excitons (Small 28/2025)

  Small · 2025-07-01 · 1 citations

  articleOpen accessSenior author

  Moiré Heterostructures In article number 2401474, Alberto de la Torre and co-workers explore how spatial variations—such as twist angle misalignment, nanoscale disorder, and atomic relaxation—impact Moiré heterostructures and their excitonic properties. They highlight advanced characterization techniques like second harmonic generation, scanning near-field optical microscopy, and laser scanning tunneling microscopy, offering insights into Moiré excitons and their potential applications in optoelectronics and quantum technologies.

  PublisherOA PDFDOI

• Flux channeling induced nano-confinement and enhancement of microwaves imaged by Rabi oscillation mapping

  ArXiv.org · 2025-01-15

  preprintOpen accessSenior author

  With rapid advances in qubit technologies, techniques for localizing, modulating, and measuring RF fields and their impact on qubit performance are of the utmost importance. Here, we demonstrate that flux-channeling from a permalloy nanowire can be used to achieve localized spatial modulation of an RF field and that the modulated field can be mapped with high resolution using the Rabi oscillations of an NV center. Rabi maps reveal ~100 mm wavelength microwaves concentrated in sub-300 nm-scale regions with up to ~16$\times$ power enhancement. This modulation is robust over a 20 dBm power range and has no adverse impact on NV $T_2$ coherence time. Micromagnetic simulations confirm that the modulated field results from the nanowire's stray field through its constructive/destructive interference with the incident RF field. Our findings provide a new pathway for controlling qubits, amplifying RF signals, and mapping local fields in various on-chip RF technologies.

  PublisherOA PDFDOI

• Bayesian Optimization with Active Constraint Learning for Advanced Manufacturing Process Design

  IISE Transactions · 2025-03-07 · 11 citations

  articleOpen access
  PublisherOA PDFDOI

• Enhanced Non‐Invasive Radio Frequency Heating Using 2D Pyrite (Pyritene)

  Small Methods · 2025-02-05 · 3 citations

  article

  Abstract Radiofrequency (RF) heating is a new, less invasive alternative to invasive heating methods that use nanoparticles for tumour therapy. But pinpoint local heating is still hard. Molecular interactions form a hybrid structure with unique electrical characteristics that enable RF heating in this work, which explores RF heating in a biological cell (yeast)‐2D FeS 2 system. Substantial processes have been uncovered via experimental investigations and density functional theory (DFT) computations. At 3 W and 50 MHz, RF heating reaches 54°C in 40 s, which is enough to kill yeast cells, while current‐voltage measurements reveal ionic diode‐like properties. Interactions between yeast lipid molecules and 2D FeS k , as shown by density‐functional theory calculations, cause an imbalance in the distribution of charges and the creation of polar, conductive channels. Insights into biological heating applications based on radio frequency (RF) technology are offered by this work, which lays forth a framework for investigating 2D material‐biomolecule interactions.

  PublisherDOI

• Flux Channeling Induced Nanoconfinement and Enhancement of Microwaves Imaged by Rabi Oscillation Mapping

  Nano Letters · 2025-06-03 · 1 citations

  articleOpen accessSenior authorCorresponding

  With rapid advances in qubit technologies, techniques for localizing, modulating, and measuring RF fields and their impact on qubit performance are of the utmost importance. Here, we demonstrate that flux-channeling from a permalloy nanowire can be used to achieve localized spatial modulation of an RF field and that the modulated field can be mapped with high resolution by using the Rabi oscillations of an NV center. Rabi maps reveal ∼100 mm wavelength microwaves concentrated in sub-300 nm regions with up to ∼16× power enhancement. This modulation is robust over a 20 dBm power range and has no adverse impact on NV T2 coherence time. Micromagnetic simulations confirm that the modulated field results from the nanowire’s stray field through its constructive/destructive interference with the incident RF field. Our findings provide a new pathway for controlling qubits, amplifying RF signals, and mapping local fields in various on-chip RF technologies.

  PublisherDOI

• Enhanced Heat Dissipation and Reduced Power Consumption in Electronics Using 2D Hexagonal Boron Nitride

  Small · 2025-06-12 · 5 citations

  preprintOpen access

  Abstract Miniaturization of electronic components has led to overheating, increased power consumption, and early circuit failures. Conventional heat dissipation methods are becoming inadequate due to limited surface area and higher short‐circuit risks. This study presents a fast, low‐cost, and scalable technique using 2D hexagonal boron nitride (hBN) coatings to enhance heat dissipation in commercial electronics. Inexpensive hBN layers, applied by drop casting or spray coating, boost thermal conductivity at IC surfaces from below 0.3 to 260 W m −1 K −1 , resulting in over double the heat flux and convective heat transfer. This significantly reduces operating temperatures and power consumption, as demonstrated by a 17.4% reduction in a coated audio amplifier circuit board. Density functional theory indicates enhanced interaction between 2D hBN and packaging materials as a key factor. This approach promises substantial energy and cost savings for large‐scale electronics without altering existing manufacturing processes.

  PublisherOA PDFDOI

• The Case for a Defect Genome Initiative

  Advanced Materials · 2024-01-09 · 20 citations

  articleOpen accessCorresponding

  The Materials Genome Initiative (MGI) has streamlined the materials discovery effort by leveraging generic traits of materials, with focus largely on perfect solids. Defects such as impurities and perturbations, however, drive many attractive functional properties of materials. The rich tapestry of charge, spin, and bonding states hosted by defects are not accessible to elements and perfect crystals, and defects can thus be viewed as another class of "elements" that lie beyond the periodic table. Accordingly, a Defect Genome Initiative (DGI) to accelerate functional defect discovery for energy, quantum information, and other applications is proposed. First, major advances made under the MGI are highlighted, followed by a delineation of pathways for accelerating the discovery and design of functional defects under the DGI. Near-term goals for the DGI are suggested. The construction of open defect platforms and design of data-driven functional defects, along with approaches for fabrication and characterization of defects, are discussed. The associated challenges and opportunities are considered and recent advances towards controlled introduction of functional defects at the atomic scale are reviewed. It is hoped this perspective will spur a community-wide interest in undertaking a DGI effort in recognition of the importance of defects in enabling unique functionalities in materials.

  PublisherOA PDFDOI

Recent grants

• Collaborative Research: Ultra-high Performance Carbon Nanotube "Parallel Nanotube Architectures" (PNAs) for On-chip Gigascale Local and Global Interconnects

  NSF · $189k · 2009–2011

• Collaborative Research: Ultra-high Performance Carbon Nanotube "Parallel Nanotube Architectures" (PNAs) for On-chip Gigascale Local and Global Interconnects

  NSF · $163k · 2010–2013

• CAREER: Graphene-based Ultra-responsive Photo-sensing Devices

  NSF · $400k · 2014–2019

• High Performance Photoswitches Using Carbon Nanotube - Si Heterojunctions for Optoelectronic Logic devices

  NSF · $317k · 2012–2016

Frequent coauthors

• Bharat Bhushan

  284 shared

• Saikat Talapatra

  Southern Illinois University Carbondale

  205 shared

• K. F. Böhringer

  University of Washington

  151 shared

• Carlos Drummond

  Université de Bordeaux

  149 shared

• Rodolfo Miranda

  Madrid Institute for Advanced Studies

  149 shared

• Amadeo L. Vázquez de Parga

  Madrid Institute for Advanced Studies

  149 shared

• Thomas Bachmann

  Humboldt-Universität zu Berlin

  148 shared

• Marina Ruths

  148 shared

Education

• PhD, Physics

  Indian Institute of Science

Awards & honors

• Patent for Color-Sensing Technology
• FY24 TIER 1 Research Development Award
• Patent for Ion and radiation detection devices based on carb…
• Creating Ion-Doped 2D Nanomaterials
• Startup Guardion Wins NASA Science Mission Directorate Chall…