TY - JOUR
T1 - Transport and excitations in a negative-U quantum dot at the LaAlO3/SrTiO3 interface
AU - Prawiroatmodjo, Guenevere E. D. K.
AU - Leijnse, Martin Christian
AU - Trier, Felix
AU - Chen, Yunzhong
AU - Christensen, Dennis Valbjørn
AU - von Soosten, Merlin
AU - Pryds, Nini
AU - Sand Jespersen, Thomas
PY - 2017
Y1 - 2017
N2 - 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 Tc
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.
AB - 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 Tc
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.
U2 - 10.1038/s41467-017-00495-7
DO - 10.1038/s41467-017-00495-7
M3 - Journal article
C2 - 28855569
SN - 2041-1723
VL - 8
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 395
ER -