Related papers

1. Stacking-induced ferroelectricity in tetralayer graphene,  2025, arXiv:2504.07935.

My work broadly investigates non‑equilibrium dynamics and phase transitions in strongly interacting quantum field theories, using the Thirring model as a representative platform. By applying variational tensor‑network methods, particularly uniform matrix product states combined with the time‑dependent variational principle, I explore how quantum phases respond to sudden changes in system parameters and how dynamical phase transitions emerge in real time. This research contributes to a broader effort to understand universal features of quantum many‑body dynamics, with results shared across several national and international workshops.

Related Presentation

1. Investigating dynamical quantum phase transitions in the massive Thirring model using matrix product states. Lattice 2023 [Link] [Pdf]

2. Thirring model from tensor networks - phase structure and real-time dynamics. 19 Nov, 2020. Perimeter Institute. [Link]

3. Phase Structure and Real-Time Dynamics of 1+1 dimensional massive Thirring model from matrix product states. 9 Dec 2020. NCTS Annual Theory Meeting 2020: Particles, Cosmology, and Strings. [Link] [Video]

Memristive devices have emerged as highly promising building blocks for brain‑inspired neuromorphic computing, owing to their intrinsic synaptic‑like behaviour, fast switching speeds, long retention times, simple device architecture, low energy consumption, and compatibility with large‑scale 3D CMOS integration. Their ability to mimic key neuronal and synaptic functions makes them attractive candidates for implementing dense, energy‑efficient artificial neural networks. In this project, we explore multifunctional memristive devices as hardware elements for neuromorphic systems, aiming to understand and harness their physical switching mechanisms to emulate aspects of human brain computation and enable scalable, hardware‑based learning architectures.

Publications

1. A. Saleem, D. Kumar, A. Singh*, S. Rajasekaran, T.-Y. Tseng, Oxygen Vacancy Transition in HfOx-Based Flexible, Robust, and Synaptic Bi-Layer Memristor for Neuromorphic and Wearable Applications. Adv. Mater. Technol. 2022, 2101208. 

2. C.-L. Hsu, A. Saleem, A. Singh, D. Kumar, and T.-Y. Tseng, “Enhanced Linearity in CBRAM Synapse by Post Oxide Deposition Annealing for Neuromorphic Computing Applications,” IEEE Trans. Electron Devices, pp. 1–7, 2021.

The goal of this project is to investigate the sensing behaviour of two‑dimensional materials and their heterostructures across multiple modalities, including gas sensing and strain sensing. We study how external stimuli—such as adsorbed gas molecules or applied mechanical deformation—modify the band structure, charge‑transfer processes, adsorption energetics, and overall electronic response of these materials. For gas sensing, we analyse adsorption and desorption dynamics, including field‑effect‑controlled desorption under gated conditions, to understand sensitivity, selectivity, and recovery behaviour. For strain sensing, we examine how lattice deformation influences polarization, carrier mobility, and conductance pathways. Together, these insights help us optimize 2D‑material‑based sensor platforms, enabling more responsive, robust, and energy‑efficient devices for environmental monitoring and mechanical sensing applications.

Publications

1. A. Singh, H. Bae, T. Hussain, H. Watanabe, H. Lee, Efficient Sensing Properties of Aluminum Nitride Nanosheets toward Toxic Pollutants under Gated Electric Field, ACS Appl. Electron. Mater. 2020 2 (6), 1645-1652 . 

2. A. Singh, H. Bae, S. Lee, K. Shabbiri, T. Hussain, H. Lee, Highly sensitive and selective sensing properties of modified green phosphorene monolayers towards SF6 decomposition gases, Appl. Surf. Sci. 512 (2020) 145641. 

3. A. Singh, S. Lee, H. Watanabe, H. Lee, Graphene-Based Ultrasensitive Strain Sensors, ACS Appl. Electron. Mater. 2 (2020) 523–528. 

The goal of this project is to investigate how two‑dimensional materials and their heterostructures respond to external perturbations through changes in their dielectric properties. We examine how intrinsic factors—such as vacancies, dipole interactions, and polarization effects—collectively influence the dielectric constant and overall electrostatic behaviour of these systems. By analysing the interplay between structural defects and dipole‑driven responses, we aim to build a deeper understanding of dielectric tunability in 2D materials, which is essential for designing next‑generation electronic, optoelectronic, and sensing devices.

Publications

1. A. Singh, S. Lee, H. Bae, J. Koo, L. Yang, H. Lee, Theoretical investigation of the vertical dielectric screening dependence on defects for few-layered van der Waals materials, RSC Adv. 9 (2019) 40309–40315. 

2. A. Singh, S. Lee, H. Lee, H. Watanabe, Dielectric Constant and van der Waals Interlayer Interaction of MoS2-Graphene Heterostructures, in: 2020 IEEE 15th Int. Conf. Nano/Micro Eng. Mol. Syst., 2020: pp. 490–494.