Controlling orbital-selective Kondo effects in a single molecule through coordination chemistry

Noriyuki Tsukahara, Emi Minamitani, Yousoo Kim, Maki Kawai, Noriaki Takagi

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

Iron(II) phthalocyanine (FePc) molecule causes novel Kondo effects derived from the unique electronic structure of multi-spins and multi-orbitals when attached to Au(111). Two unpaired electrons in the dz2 and the degenerate dπ orbitals are screened stepwise, resulting in spin and spin+orbital Kondo effects, respectively. We investigated the impact on the Kondo effects of the coordination of CO and NO molecules to the Fe2+ ion as chemical stimuli by using scanning tunneling microscopy (STM) and density functional theory calculations. The impacts of the two diatomic molecules are different from each other as a result of the different electronic configurations. The coordination of CO converts the spin state from triplet to singlet, and then the Kondo effects completely disappear. In contrast, an unpaired electron survives in the molecular orbital composed of Fe d z2 and NO 5σ and 2π* orbitals for the coordination of NO, causing a sharp Kondo resonance. The isotropic magnetic response of the peak indicates the origin is the spin Kondo effect. The diatomic molecules attached to the Fe2+ ion were easily detached by applying a pulsed voltage at the STM junction. These results demonstrate that the single molecule chemistry enables us to switch and control the spin and the many-body quantum states reversibly.

Original languageEnglish
Article number054702
JournalJournal of Chemical Physics
Volume141
Issue number5
DOIs
Publication statusPublished - 2014 Aug 7

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Controlling orbital-selective Kondo effects in a single molecule through coordination chemistry'. Together they form a unique fingerprint.

Cite this