Speaker
Description
Since the discovery of graphene, two-dimensional (2D) materials with different properties—ranging from semiconductors to superconductors and magnets—have been isolated. A defining characteristic of these materials is their sensitivity to external perturbations, which makes them highly tunable. Strain engineering is a powerful tool that leverages the mechanical flexibility of 2D materials to modulate their electronic, optical, and magnetic responses. While the tuning of semiconducting properties has been extensively explored at room temperature, strain effects on quantum phenomena—including superconductivity and magnetism—remain comparatively unexplored, despite strong theoretical predictions suggesting that strain can modulate or even induce emergent phase transitions. This is partially due to the lack of suitable methods to apply controlled strain in 2D materials at low temperatures, where many of these quantum phenomena emerge.
In this talk, I will present a series of recent experiments that overcome these challenges by using thermal mismatch with polymeric substrates to induce uniform, biaxial compressive strain in 2D crystals under cryogenic conditions. This approach enables a robust strain-driven modulation of quantum phenomena across different material systems. I will show how strain can be used to tune neutral and charged excitons in monolayer transition metal dichalcogenides [1], shift the superconducting transition in few-layer NbSe₂ [2], and enhance magnetoresistance and magnetic anisotropy in the antiferromagnetic semiconductor CrSBr [3]. Our approach provides a straightforward method to tune and control phase transitions and quantum properties in 2D materials at cryogenic temperatures. Our findings highlight the potential of strain engineering to adjust the properties of 2D materials for spintronics and quantum technology applications.
[1] E. Henriquez-Guerra et al., Large Biaxial Compressive Strain Tuning of Neutral and Charged Excitons in Single-Layer Transition Metal Dichalcogenides, ACS Applied Materials & Interfaces 2023 15 (49), 57369-57378.
[2] E. Henriquez-Guerra et al. Modulation of the Superconducting Phase Transition in Multilayer 2H-NbSe2 Induced by Uniform Biaxial Compressive Strain Nano Letters 2024 24 (34), 10504-10509
[3] E. Henriquez-Guerra et al. Strain Engineering of Magnetoresistance and Magnetic Anisotropy in CrSBr. Advanced Materials 2025, 2506695.