{"id":{"repo_id":"buffalo","oai_identifier":"oai:ubir.buffalo.edu:10477/78399"},"canonical_url":"https://search.dev.ndltd.org/etd/buffalo/oai:ubir.buffalo.edu:10477/78399","repository":{"repo_id":"buffalo","name":"Buffalo","base_url":"https://ubir.buffalo.edu/oai/request"},"display":{"title":"Polarization-sensitive infrared magneto-optical studies in two-dimensional materials ranging from graphene to high Tc superconductors","abstract":"Ph.D.","abstract_html":"Ph.D.","abstract_has_math":false,"creators":["Mukherjee, Alok"],"institution":"State University of New York at Buffalo","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Cerne, John","Physics"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-10-23T19:43:11Z","date_published":"2018-10-23T19:43:11Z","updated_at":"2026-07-27T19:05:09Z","subjects":["condensed matter physics"],"languages":["eng"],"rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10477/78399","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Cerne, John","Physics"]},{"key":"dc:creator","label":"Author","values":["Mukherjee, Alok"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018-10-23T19:43:11Z","2018","2018-06-07 16:13:44"]},{"key":"dc:publisher","label":"Institution","values":["State University of New York at Buffalo"]},{"key":"dc:type","label":"Dc Type","values":["Text","Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["condensed matter physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/10477/78399"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ph.D.","This Dissertation presents experimental mid-infrared Faraday and Kerr effect studies of a variety of materials: graphene, Al-doped ferromagnetic SiC, high Tc cuprate superconductors (YBCO, LSCO, LBCO) and iron-based superconductors (BaFe2As2). The Faraday and Kerr effects are optical analogs of the Hall effect and are sensitive to the off-diagonal conductivity. By measuring the polarization of the transmitted (Faraday) and reflected (Kerr) radiation, these measurements are sensitive to the underlying symmetries of the system. The main goal of this research is to explore the symmetries that can give us new insights into novel materials. The main challenge in measuring the Faraday and Kerr response of a material lies in the ability to measure tiny changes in the polarization of transmitted/reflected light. Using a unique magneto-polarimetry setup we have measured Faraday/Kerr angles as small as. The primary results of this work include the discovery of a colossal enhancement of the magneto-optical Kerr effect in films on SiC. In epitaxial graphene, the Kerr response gets enhanced by a factor of 68 near the reststrahlen band of SiC. The enhancement effect works for any polar substrate and provides a new way of enhancing the infrared Kerr response from complex materials in which the signal usually is very small. Moreover, we predict enhancement in Faraday response in films grown on metamaterials.By studying the changes in the polarization of reflected light in epitaxial graphene grown on terraced substrates of SiC, we also have discovered Kerr rotation and ellipticity at zero magnetic field. This optical effect originates from the anisotropy in graphene’s conductance when it grows over a terraced substrate like SiC, acting as a wire-grid linear polarizer and producing a Kerr signal even in the absence of an external magnetic field. Proposed next-generation displays will combine liquid crystals and graphene, so understanding the polarizing properties of graphene is also important for technological applications. Our technique of measuring the polarization properties of graphene at zero magnetic field and at room temperature gives a new contactless- noninvasive way of probing the anisotropy of graphene. We also explore broken symmetry states in high-temperature cuprate superconductors (HTCS) by measuring the zero-field Faraday response. In HTCS we have found linear dichroism (preferential absorption of light polarized along one axis) in mid-infrared and also at visible wavelengths at room temperature and down to . Earlier studies in THz and near IR have shown that the signal in HTSC is linked to different broken symmetries in the pseudogap region such as stripes. The Faraday rotation signal is strongest in underdoped films, depending on both temperature and sample orientation, which suggests that there is linear symmetry breaking in the pseudogap region. With its sensitivity to electronic structure and magnetic ordering, we have studied Faraday response in iron-based pnictide superconductors to understand the interaction of superconductivity (SC) and ferromagnetism (FM). Faraday and Kerr effects studies have been used in the past to explore these two phenomena separately. The pnictide (Co-doped BaFe2As2), films that we have studied show both SC and FM behavior. We use the frequency and temperature dependence of our Faraday response measurements to explore how the SC and FM phases interact with each other."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Polarization-sensitive infrared magneto-optical studies in two-dimensional materials ranging from graphene to high Tc superconductors"]}]}],"canonical_facts":{"dc:contributor":["Cerne, John","Physics"],"dc:creator":["Mukherjee, Alok"],"dc:date":["2018-10-23T19:43:11Z","2018","2018-06-07 16:13:44"],"dc:description":["Ph.D.","This Dissertation presents experimental mid-infrared Faraday and Kerr effect studies of a variety of materials: graphene, Al-doped ferromagnetic SiC, high Tc cuprate superconductors (YBCO, LSCO, LBCO) and iron-based superconductors (BaFe2As2). The Faraday and Kerr effects are optical analogs of the Hall effect and are sensitive to the off-diagonal conductivity. By measuring the polarization of the transmitted (Faraday) and reflected (Kerr) radiation, these measurements are sensitive to the underlying symmetries of the system. The main goal of this research is to explore the symmetries that can give us new insights into novel materials. The main challenge in measuring the Faraday and Kerr response of a material lies in the ability to measure tiny changes in the polarization of transmitted/reflected light. Using a unique magneto-polarimetry setup we have measured Faraday/Kerr angles as small as. The primary results of this work include the discovery of a colossal enhancement of the magneto-optical Kerr effect in films on SiC. In epitaxial graphene, the Kerr response gets enhanced by a factor of 68 near the reststrahlen band of SiC. The enhancement effect works for any polar substrate and provides a new way of enhancing the infrared Kerr response from complex materials in which the signal usually is very small. Moreover, we predict enhancement in Faraday response in films grown on metamaterials.By studying the changes in the polarization of reflected light in epitaxial graphene grown on terraced substrates of SiC, we also have discovered Kerr rotation and ellipticity at zero magnetic field. This optical effect originates from the anisotropy in graphene’s conductance when it grows over a terraced substrate like SiC, acting as a wire-grid linear polarizer and producing a Kerr signal even in the absence of an external magnetic field. Proposed next-generation displays will combine liquid crystals and graphene, so understanding the polarizing properties of graphene is also important for technological applications. Our technique of measuring the polarization properties of graphene at zero magnetic field and at room temperature gives a new contactless- noninvasive way of probing the anisotropy of graphene. We also explore broken symmetry states in high-temperature cuprate superconductors (HTCS) by measuring the zero-field Faraday response. In HTCS we have found linear dichroism (preferential absorption of light polarized along one axis) in mid-infrared and also at visible wavelengths at room temperature and down to . Earlier studies in THz and near IR have shown that the signal in HTSC is linked to different broken symmetries in the pseudogap region such as stripes. The Faraday rotation signal is strongest in underdoped films, depending on both temperature and sample orientation, which suggests that there is linear symmetry breaking in the pseudogap region. With its sensitivity to electronic structure and magnetic ordering, we have studied Faraday response in iron-based pnictide superconductors to understand the interaction of superconductivity (SC) and ferromagnetism (FM). Faraday and Kerr effects studies have been used in the past to explore these two phenomena separately. The pnictide (Co-doped BaFe2As2), films that we have studied show both SC and FM behavior. We use the frequency and temperature dependence of our Faraday response measurements to explore how the SC and FM phases interact with each other."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/10477/78399"],"dc:language":["eng"],"dc:publisher":["State University of New York at Buffalo"],"dc:rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"dc:subject":["condensed matter physics"],"dc:title":["Polarization-sensitive infrared magneto-optical studies in two-dimensional materials ranging from graphene to high Tc superconductors"],"dc:type":["Text","Dissertation"]},"updated_at":"2026-07-27T19:05:09Z"}