skip to main content

DOE PAGESDOE PAGES

Title: Emergent chirality in the electric polarization texture of titanate superlattices

Chirality is a geometrical property by which an object is not super-imposable onto its mirror image, thereby imparting a handedness. Chirality determines many important properties in nature—from the strength of the weak interactions according to the electroweak theory in particle physics to the binding of enzymes with naturally occurring amino acids or sugars, reactions that are fundamental for life. In condensed matter physics, the prediction of topologically protected magnetic skyrmions and related spin textures in chiral magnets has stimulated significant research. If the magnetic dipoles were replaced by their electrical counterparts, then electrically controllable chiral devices could be designed. Complex oxide BaTiO 3/SrTiO 3 nanocomposites and PbTiO 3/SrTiO 3 superlattices are perfect candidates, since “polar vortices,” in which a continuous rotation of ferroelectric polarization spontaneously forms, have been recently discovered. Using resonant soft X-ray diffraction, we report the observation of a strong circular dichroism from the interaction between circularly polarized light and the chiral electric polarization texture that emerges in PbTiO 3/SrTiO 3 superlattices. This hallmark of chirality is explained by a helical rotation of electric polarization that second-principles simulations predict to reside within complex 3D polarization textures comprising ordered topological line defects. The handedness of the texture can bemore » topologically characterized by the sign of the helicity number of the chiral line defects. Furthermore, this coupling between the optical and novel polar properties could be exploited to encode chiral signatures into photon or electron beams for information processing.« less
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [4] ; ORCiD logo [4] ;  [5] ;  [5] ;  [6] ;  [7] ;  [5] ;  [8] ;  [2] ;  [5]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Univ. de Cantabria, Santander (Spain)
  3. Univ. del Pais Vasco, San Sebastian (Spain); Queen’s Univ. Belfast, Belfast (United Kingdom)
  4. Univ. of California, Berkeley, CA (United States)
  5. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  6. Institut de Ciencia de Materials de Barcelona, Bellaterra (Spain)
  7. Luxembourg Institute of Science and Technology, Esch/Alzette (Luxembourg)
  8. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-05CH11231; SC0012375
Type:
Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 115; Journal Issue: 5; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; chirality; electric polarization; topological textures; resonant soft X-ray diffraction; second-principles calculations
OSTI Identifier:
1417088
Alternate Identifier(s):
OSTI ID: 1465698

Shafer, Padraic, García-Fernández, Pablo, Aguado-Puente, Pablo, Damodaran, Anoop R., Yadav, Ajay K., Nelson, Christopher T., Hsu, Shang -Lin, Wojdeł, Jacek C., Íñiguez, Jorge, Martin, Lane W., Arenholz, Elke, Junquera, Javier, and Ramesh, Ramamoorthy. Emergent chirality in the electric polarization texture of titanate superlattices. United States: N. p., Web. doi:10.1073/pnas.1711652115.
Shafer, Padraic, García-Fernández, Pablo, Aguado-Puente, Pablo, Damodaran, Anoop R., Yadav, Ajay K., Nelson, Christopher T., Hsu, Shang -Lin, Wojdeł, Jacek C., Íñiguez, Jorge, Martin, Lane W., Arenholz, Elke, Junquera, Javier, & Ramesh, Ramamoorthy. Emergent chirality in the electric polarization texture of titanate superlattices. United States. doi:10.1073/pnas.1711652115.
Shafer, Padraic, García-Fernández, Pablo, Aguado-Puente, Pablo, Damodaran, Anoop R., Yadav, Ajay K., Nelson, Christopher T., Hsu, Shang -Lin, Wojdeł, Jacek C., Íñiguez, Jorge, Martin, Lane W., Arenholz, Elke, Junquera, Javier, and Ramesh, Ramamoorthy. 2018. "Emergent chirality in the electric polarization texture of titanate superlattices". United States. doi:10.1073/pnas.1711652115.
@article{osti_1417088,
title = {Emergent chirality in the electric polarization texture of titanate superlattices},
author = {Shafer, Padraic and García-Fernández, Pablo and Aguado-Puente, Pablo and Damodaran, Anoop R. and Yadav, Ajay K. and Nelson, Christopher T. and Hsu, Shang -Lin and Wojdeł, Jacek C. and Íñiguez, Jorge and Martin, Lane W. and Arenholz, Elke and Junquera, Javier and Ramesh, Ramamoorthy},
abstractNote = {Chirality is a geometrical property by which an object is not super-imposable onto its mirror image, thereby imparting a handedness. Chirality determines many important properties in nature—from the strength of the weak interactions according to the electroweak theory in particle physics to the binding of enzymes with naturally occurring amino acids or sugars, reactions that are fundamental for life. In condensed matter physics, the prediction of topologically protected magnetic skyrmions and related spin textures in chiral magnets has stimulated significant research. If the magnetic dipoles were replaced by their electrical counterparts, then electrically controllable chiral devices could be designed. Complex oxide BaTiO3/SrTiO3 nanocomposites and PbTiO3/SrTiO3 superlattices are perfect candidates, since “polar vortices,” in which a continuous rotation of ferroelectric polarization spontaneously forms, have been recently discovered. Using resonant soft X-ray diffraction, we report the observation of a strong circular dichroism from the interaction between circularly polarized light and the chiral electric polarization texture that emerges in PbTiO3/SrTiO3 superlattices. This hallmark of chirality is explained by a helical rotation of electric polarization that second-principles simulations predict to reside within complex 3D polarization textures comprising ordered topological line defects. The handedness of the texture can be topologically characterized by the sign of the helicity number of the chiral line defects. Furthermore, this coupling between the optical and novel polar properties could be exploited to encode chiral signatures into photon or electron beams for information processing.},
doi = {10.1073/pnas.1711652115},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 5,
volume = 115,
place = {United States},
year = {2018},
month = {1}
}

Works referenced in this record:

Oxide Interfaces--An Opportunity for Electronics
journal, March 2010

Spontaneous skyrmion ground states in magnetic metals
journal, August 2006
  • R��ler, U. K.; Bogdanov, A. N.; Pfleiderer, C.
  • Nature, Vol. 442, Issue 7104, p. 797-801
  • DOI: 10.1038/nature05056