Transport and excitations in a negative-U quantum dot at the LaAlO3/SrTiO3 interface
(2017) In Nature Communications 8(1).- Abstract
In a solid-state host, attractive electron-electron interactions can lead to the formation of local electron pairs which play an important role in the understanding of prominent phenomena such as high T c superconductivity and the pseudogap phase. Recently, evidence of a paired ground state without superconductivity was demonstrated at the level of single electrons in quantum dots at the interface of LaAlO3 and SrTiO3. Here, we present a detailed study of the excitation spectrum and transport processes of a gate-defined LaAlO3/SrTiO3 quantum dot exhibiting pairing at low temperatures. For weak tunneling, the spectrum agrees with calculations based on the Anderson model with a... (More)
In a solid-state host, attractive electron-electron interactions can lead to the formation of local electron pairs which play an important role in the understanding of prominent phenomena such as high T c superconductivity and the pseudogap phase. Recently, evidence of a paired ground state without superconductivity was demonstrated at the level of single electrons in quantum dots at the interface of LaAlO3 and SrTiO3. Here, we present a detailed study of the excitation spectrum and transport processes of a gate-defined LaAlO3/SrTiO3 quantum dot exhibiting pairing at low temperatures. For weak tunneling, the spectrum agrees with calculations based on the Anderson model with a negative effective charging energy U, and exhibits an energy gap corresponding to the Zeeman energy of the magnetic pair-breaking field. In contrast, for strong coupling, low-bias conductance is enhanced with a characteristic dependence on temperature, magnetic field and chemical potential consistent with the charge Kondo effect.
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- author
- Prawiroatmodjo, Guenevere E.D.K. ; Leijnse, Martin LU ; Trier, Felix ; Chen, Yunzhong ; Christensen, Dennis V. ; Von Soosten, Merlin ; Pryds, Nini and Jespersen, Thomas S.
- organization
- publishing date
- 2017-12-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Nature Communications
- volume
- 8
- issue
- 1
- article number
- 395
- publisher
- Nature Publishing Group
- external identifiers
-
- pmid:28855569
- wos:000408695100012
- scopus:85028547465
- ISSN
- 2041-1723
- DOI
- 10.1038/s41467-017-00495-7
- language
- English
- LU publication?
- yes
- id
- fbf90b1c-bccd-41fe-bafd-7ae35a2b6e87
- date added to LUP
- 2017-09-25 14:01:45
- date last changed
- 2024-02-29 22:15:31
@article{fbf90b1c-bccd-41fe-bafd-7ae35a2b6e87, abstract = {{<p>In a solid-state host, attractive electron-electron interactions can lead to the formation of local electron pairs which play an important role in the understanding of prominent phenomena such as high T <sub>c</sub> superconductivity and the pseudogap phase. Recently, evidence of a paired ground state without superconductivity was demonstrated at the level of single electrons in quantum dots at the interface of LaAlO<sub>3</sub> and SrTiO<sub>3</sub>. Here, we present a detailed study of the excitation spectrum and transport processes of a gate-defined LaAlO<sub>3</sub>/SrTiO<sub>3</sub> quantum dot exhibiting pairing at low temperatures. For weak tunneling, the spectrum agrees with calculations based on the Anderson model with a negative effective charging energy U, and exhibits an energy gap corresponding to the Zeeman energy of the magnetic pair-breaking field. In contrast, for strong coupling, low-bias conductance is enhanced with a characteristic dependence on temperature, magnetic field and chemical potential consistent with the charge Kondo effect.</p>}}, author = {{Prawiroatmodjo, Guenevere E.D.K. and Leijnse, Martin and Trier, Felix and Chen, Yunzhong and Christensen, Dennis V. and Von Soosten, Merlin and Pryds, Nini and Jespersen, Thomas S.}}, issn = {{2041-1723}}, language = {{eng}}, month = {{12}}, number = {{1}}, publisher = {{Nature Publishing Group}}, series = {{Nature Communications}}, title = {{Transport and excitations in a negative-U quantum dot at the LaAlO<sub>3</sub>/SrTiO<sub>3</sub> interface}}, url = {{http://dx.doi.org/10.1038/s41467-017-00495-7}}, doi = {{10.1038/s41467-017-00495-7}}, volume = {{8}}, year = {{2017}}, }