Nanomaterials:
Nanomaterials are small structures with length-scale ranging from 1 to 100 nm, which often present unique physical and chemical properties compared to their macroscopic counterparts. At the nanoscale, the arrangement of atoms can directly determine material properties. Understanding how different arrangements can lead to certain material behaviors and how to optimize their properties for engineering applications is crucial for modern nanotechnology. In our lab, we apply different simulation methodologies to investigate various nano- and micro-systems to help advance their applications in energy harvesting, sensors, electronic devices, etc.
Representative publications:
- J. Ma, Y. Ni, S. Volz, T. Dumitrica, Thermal transport in single-walled carbon nanotubes under pure bending, Physical Review Applied 3 (2), 024014 (2015)
- J. Ma, Y. Ni, T. Dumitrica, Nanowires with Dislocations for Ultralow Lattice Thermal Conductivity, Physical Chemistry Chemical Physics, 18(15), 9888-9892 (2016)
- J. Ma, J.-M. Carrillo, C. Do, W.-R. Chen, P. Falus, Z. Shen, K. Hong, B. G. Sumpter, Y. Wang, Spatial correlations of entangled polymer dynamics, Physical Review E 104 (2), 024503 (2021)†
Metamaterials:
Meta, in Greek, means beyond. Metamaterials are artificially structured materials that are composed of repeated patterns, or unit cells. By carefully designing these unit cells, we will be able to achieve unconventional properties rarely found in nature, such as topologically-protected edge states, negative index of refraction, and negative Poisson ratio. These attributes make them attractive for a variety of emerging technological applications such as wave manipulation, cloaking, smart sensing, and imaging. Here, we will use a combination of theoretical analysis, computational simulation, and experimental characterization to explore and uncover these transformative materials.
Representative publications:
- J. Ma, D. Zhou, K. Sun, X. Mao, S. Gonella, Edge Modes and Asymmetric Wave Transport in Topological Lattices: Experimental Characterization at Finite Frequencies, Physical Review Letters 121 (9), 094301 (2018)
- J. Ma, K. Sun, S. Gonella, Valley-Hall In-Plane Edge States as Building Blocks for Elastodynamic Logic Circuits, Physical Review Applied, 12 (4), 044015 (2019)
- A. Rajabpoor Alisepahi, S. Sarkar, K. Sun, J. Ma. Breakdown of Conventional Winding Number Calculation in One-Dimensional Lattices with Interactions Beyond Nearest Neighbors. Communications Physics, 6, 334, (2023).
We acknowledge the following federal agencies for the funding of our research:
