Interplay between electronic nematicity and elasticity in finite-size samples and surfaces
2021-05
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Interplay between electronic nematicity and elasticity in finite-size samples and surfaces
Authors
Published Date
2021-05
Publisher
Type
Thesis or Dissertation
Abstract
In the phase diagram of iron-based superconductors, the proximity of superconductivityto electronic nematicity, the spontaneous breaking of the discrete rotational symmetry,
has prompted numerous studies of a detailed understanding of nematicity and its interplay
with superconductivity. Several studies have suggested the onset of nematic order
above the bulk nematic critical temperature, along with indications of it being associated with the surface of the sample. In this work, motivated by the strong nemato-elastic interaction, we consider aspects of the interplay of elasticity and nematicity in realistic finite-size samples, considering both bulk and surface effects. First, we demonstrate non-trivial boundary effects in a finite-size sample, which significantly alter the order parameter profiles and the critical temperature. Elaborate finite-element simulations are carried out to solve the full nemato-elastic problem, demonstrating a strong inhomogeneity, dependent on the sample aspect ratio and geometric constraints. We find that the nematic critical temperature is bounded by the corresponding bulk value and, in fact, decreases rapidly with decreasing sample thickness, thereby necessitating the presence of other mechanisms to generate supercritical nematicity. We propose surface elastic disorder, such as domains of anisotropic defects, as possible avenues to realize supercritical nematicity. We show that these, in fact, lead to an incommensurate supercritical smectic state, localized at the sample surface, eventually transitioning into the standard uniform bulk nematic state. The smectic modulation wavevector is dependent only on the elastic parameters, and the coefficients entering the nematic free energy.
Description
University of Minnesota M.S. thesis. May 2021. Major: Physics. Advisor: Rafael Fernandes. 1 computer file (PDF); v, 77 pages.
Related to
Replaces
License
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Lahiri, Aritra. (2021). Interplay between electronic nematicity and elasticity in finite-size samples and surfaces. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/224894.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.