Patrick Krantz; Alex Tyner; Pallab Goswami; Venkat Chandrasekhar
Colossal Spontaneous Hall Effect and Emergent Magnetism in KTaO3 Two-Dimensional Electron Gases Journal Article
In: 2022.
Abstract | Links | BibTeX | Tags: AMR, magnetic impurity, Magnetism, perovskite, Superconductivity
@article{nokey,
title = {Colossal Spontaneous Hall Effect and Emergent Magnetism in KTaO3 Two-Dimensional Electron Gases},
author = {Patrick Krantz and Alex Tyner and Pallab Goswami and Venkat Chandrasekhar},
url = {https://arxiv.org/abs/2209.10534},
year = {2022},
date = {2022-09-21},
urldate = {2022-09-21},
abstract = {There has been intense recent interest in the two-dimensional electron gases (2DEGs) that form at the surfaces and interfaces of KTaO$_3$ (KTO), with the discovery of superconductivity at temperatures significantly higher than those of similar 2DEGs based on SrTiO$_3$ (STO). Here we demonstrate that KTO 2DEGs fabricated under conditions that suppress the superconductivity show a large spontaneous Hall effect at low temperatures. The transverse response is asymmetric in an applied perpendicular magnetic field and becomes hysteretic at millikelvin temperatures. The hysteresis is due to long range magnetic order arising from local Ta$^{4+}$ moments. However, the most striking features of the data are the asymmetry of the transverse response and the large spontaneous transverse resistance at zero field, which can be a significant fraction of the longitudinal resistance and depends on crystal orientation. Both effects are due to the presence of a dominant contribution to the transverse response that is symmetric in perpendicular field, suggesting that its origin is topological in nature. We argue that this contribution arises from Berry curvature dipoles coupled with nonequilibrium conditions induced by the measuring current.},
keywords = {AMR, magnetic impurity, Magnetism, perovskite, Superconductivity},
pubstate = {published},
tppubtype = {article}
}
There has been intense recent interest in the two-dimensional electron gases (2DEGs) that form at the surfaces and interfaces of KTaO$_3$ (KTO), with the discovery of superconductivity at temperatures significantly higher than those of similar 2DEGs based on SrTiO$_3$ (STO). Here we demonstrate that KTO 2DEGs fabricated under conditions that suppress the superconductivity show a large spontaneous Hall effect at low temperatures. The transverse response is asymmetric in an applied perpendicular magnetic field and becomes hysteretic at millikelvin temperatures. The hysteresis is due to long range magnetic order arising from local Ta$^{4+}$ moments. However, the most striking features of the data are the asymmetry of the transverse response and the large spontaneous transverse resistance at zero field, which can be a significant fraction of the longitudinal resistance and depends on crystal orientation. Both effects are due to the presence of a dominant contribution to the transverse response that is symmetric in perpendicular field, suggesting that its origin is topological in nature. We argue that this contribution arises from Berry curvature dipoles coupled with nonequilibrium conditions induced by the measuring current.
Manan Mehta
Interplay between superconductivity and ferromagnetism at the LaAlO3/SrTiO3 interface PhD Thesis
2015.
Links | BibTeX | Tags: AMR, epitaxial, Kondo effect, Magnetic force microscopy, Magnetism, Mesoscopic quantum transport, scanning probe, Superconductivity, vortex dynamics
@phdthesis{Mehta2015,
title = {Interplay between superconductivity and ferromagnetism at the LaAlO3/SrTiO3 interface},
author = {Manan Mehta},
url = {http://www.nano.northwestern.edu/wp-content/uploads/2017/09/Manan_Mehta_PhD_Thesis.pdf},
year = {2015},
date = {2015-12-01},
keywords = {AMR, epitaxial, Kondo effect, Magnetic force microscopy, Magnetism, Mesoscopic quantum transport, scanning probe, Superconductivity, vortex dynamics},
pubstate = {published},
tppubtype = {phdthesis}
}
Alexandra R. Cunliffe
2009.
Links | BibTeX | Tags: AMR, epitaxial, FMR, Magnetic force microscopy, Magnetism, nanomagnets, perovskite, scanning probe
@mastersthesis{Cunliffe2009,
title = {Magnetoelectric cobalt ferrite/bismuth ferrite hybrid nanostructures: Progress towards achieving electric field control of magnetization},
author = {Alexandra R. Cunliffe},
url = {http://www.nano.northwestern.edu/wp-content/uploads/2017/09/Senior_Thesis.pdf},
year = {2009},
date = {2009-05-01},
keywords = {AMR, epitaxial, FMR, Magnetic force microscopy, Magnetism, nanomagnets, perovskite, scanning probe},
pubstate = {published},
tppubtype = {mastersthesis}
}
José Aumentado
2000.
Links | BibTeX | Tags: AMR, Andreev reflection, charge imbalance, crossed andreev reflection, Magnetism, Mesoscopic quantum transport, phase coherence, Proximity effect, spin transport
@phdthesis{Aumentado2000,
title = {Nonequilibrium and Quantum Transport Phenomena in Mesoscopic Ferromagnet/Superconductor Heterostructures},
author = {José Aumentado},
url = {http://www.nano.northwestern.edu/wp-content/uploads/2017/09/AumentadoThesis.pdf},
year = {2000},
date = {2000-12-01},
keywords = {AMR, Andreev reflection, charge imbalance, crossed andreev reflection, Magnetism, Mesoscopic quantum transport, phase coherence, Proximity effect, spin transport},
pubstate = {published},
tppubtype = {phdthesis}
}
J Aumentado; V Chandrasekhar
Magnetotransport in mesoscopic ferromagnetic particles Journal Article
In: Physica B: Condensed Matter, vol. 284–288, Part 2, pp. 1742–1743, 2000, ISSN: 0921-4526.
Abstract | Links | BibTeX | Tags: AMR, Magnetism
@article{aumentado_magnetotransport_2000,
title = {Magnetotransport in mesoscopic ferromagnetic particles},
author = { J Aumentado and V Chandrasekhar},
url = {http://www.sciencedirect.com/science/article/pii/S0921452699029087},
doi = {10.1016/S0921-4526(99)02908-7},
issn = {0921-4526},
year = {2000},
date = {2000-07-01},
urldate = {2016-12-28},
journal = {Physica B: Condensed Matter},
volume = {284–288, Part 2},
pages = {1742--1743},
abstract = {We have measured the magnetoresistance of submicron elliptical Ni particles with Au probes. In addition to the classical anisotropic magnetoresistance (AMR), we also observe conductance fluctuations and an asymmetry with respect to magnetic field which is associated with the four terminal nature of our measurements.},
keywords = {AMR, Magnetism},
pubstate = {published},
tppubtype = {article}
}
We have measured the magnetoresistance of submicron elliptical Ni particles with Au probes. In addition to the classical anisotropic magnetoresistance (AMR), we also observe conductance fluctuations and an asymmetry with respect to magnetic field which is associated with the four terminal nature of our measurements.
J. Aumentado; V. Chandrasekhar
Magnetoresistance of single-domain ferromagnetic particles Journal Article
In: Applied physics letters, vol. 74, no. 13, pp. 1898–1900, 1999.
Links | BibTeX | Tags: AMR, Magnetism, nanomagnets
@article{aumentado_magnetoresistance_1999,
title = {Magnetoresistance of single-domain ferromagnetic particles},
author = { J. Aumentado and V. Chandrasekhar},
url = {http://scitation.aip.org/content/aip/journal/apl/74/13/10.1063/1.123706},
year = {1999},
date = {1999-01-01},
urldate = {2016-12-29},
journal = {Applied physics letters},
volume = {74},
number = {13},
pages = {1898--1900},
keywords = {AMR, Magnetism, nanomagnets},
pubstate = {published},
tppubtype = {article}
}
