Tuning the Kondo effect via gating-controlled orbital selection in the LaAlO3/SrTiO3 interfacial d -electron system

Yan，Yuedong1,2; Guo，Linhai1,2; Li，Lin3; Wei，Laiming1,2; Chen，Weiqiang4; Zeng，Changgan1,2; Hou，Jianguo1

2020-01-13

10.1103/PhysRevB.101.035119

PHYSICAL REVIEW B   影响因子和分区

2469-9950

2469-9969

The orbital degree of freedom plays a critical role in contemporary condensed-matter physics, with recent discoveries of orbital-dependent many-body effects including electron correlation and superconductivity. Nevertheless, these orbital-dependent many-body effects have mainly been observed in bulk materials, wherein the electrons' orbital attribute is challenging to tailor selectively. Here, by planar tunneling into the two-dimensional electron system (2DES) at the LaAlO3/SrTiO3 interface, we observed a Kondo resonance, a model many-body phenomenon. The observation of the Kondo resonance provides an ideal opportunity to quantitatively exploit the emerging interfacial Kondo physics. Furthermore, it was found that the Kondo coupling strength and resonance line shape can be effectively regulated by electrostatic gating and show a sharp transition at the Lifshitz point, where the orbital occupancy of the 2DES changes from only dxy to both dxy and dxz/yz. This unusual behavior is attributed to the orbital selectivity effect in this unique multiple-d-band system, wherein the itinerant dxy and dxz/yz electrons have different orbital symmetries and therefore different Kondo exchange coupling with the localized dxy electrons. The present study may pave the way for manipulating many-body effects in 2D multiband materials via orbital engineering of itinerant electrons.

SCI ; EI

英语

其他

Natural Science Foundation of Anhui Province[1708085MF136] ; [2017YFA0403600] ; [AHY170000] ; [2018HSC-UE014] ; National Natural Science Foundation of China[11974324]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000506844100005

American Physical Society

20200508095914

Degrees of freedom (mechanics) ; Resonance

Mechanics:931.1

PHYSICS

2-s2.0-85078470781

Scopus

1.International Center for Quantum Design of Functional Materials,Hefei National Laboratory for Physical Sciences at the Microscale,Synergetic Innovation Center of Quantum Information and Quantum Physics,University of Science and Technology of China,Hefei, Anhui,230026,China
2.CAS,Key Laboratory of Strongly-Coupled Quantum Matter Physics,Department of Physics,University of Science and Technology of China,Hefei, Anhui,230026,China
3.College of Physics and Electronic Engineering,Center for Computational Sciences,Sichuan Normal University,Chengdu, Sichuan,610068,China
4.Institute for Quantum Science and Engineering,Department of Physics,Southern University of Science and Technology of China,Shenzhen, Guangdong,518055,China

Yan，Yuedong,Guo，Linhai,Li，Lin,et al. Tuning the Kondo effect via gating-controlled orbital selection in the LaAlO3/SrTiO3 interfacial d -electron system[J]. PHYSICAL REVIEW B,2020,101(3).

Yan，Yuedong.,Guo，Linhai.,Li，Lin.,Wei，Laiming.,Chen，Weiqiang.,...&Hou，Jianguo.(2020).Tuning the Kondo effect via gating-controlled orbital selection in the LaAlO3/SrTiO3 interfacial d -electron system.PHYSICAL REVIEW B,101(3).

Yan，Yuedong,et al."Tuning the Kondo effect via gating-controlled orbital selection in the LaAlO3/SrTiO3 interfacial d -electron system".PHYSICAL REVIEW B 101.3(2020).