Magnetism at the nanoscale: Engineering spin and correlations with an atomically precise probe
DIPC Seminars
- Speaker
-
Dr. Markus Ternes, Max Planck Institute for solid state research, Stuttgart, Germany
- When
-
2017/07/24
14:00 - Place
- Donostia International Physics Center
- Add to calendar
- iCal
In recent years
inelastic spin-flip spectroscopy using low-temperature scanning tunneling
microscopes has been a very successful tool for studying not only individual
spins but also complexly coupled systems. The spin-bearing molecules can be
stabilized on surfaces and in junctions with desirable properties that can be
adjusted by external stimuli. When these systems interact with the electrons of
the supporting electrodes correlated many-particle states can emerge, making
them ideal prototypical quantum systems.
In this
presentation I will show how effective _S_ = 1 and _S_ = 1/2 model
systems of cobalt hydrates (CoHx) on a _h_ -BN/Rh(111) substrate
[1] in conjunction with model Hamiltonians [2, 3] can be used to explore this
interesting quantum world. In detail I will discuss the manipulation of the
total spin of the cobalt complexes by using a H-functionalized scanning probe
tip [4]. When the additional hydrogen ligand is brought close to the CoH,
switching between a correlated _S_ = 1/2 Kondo state and a _S_ = 1 state
with magnetic anisotropy is observed. By simultaneously tracking the exchange
force and conductance during the spin change we explore in detail the
transition mechanism.
Furthermore, I
will outline how the controlled coupling of individual spin systems can lead
not only to an energy shift of the eigenstates reminiscent of an externally
applied field, but also to a bias asymmetry in the differential conductance due
to spin-spin correlations with the environment [5]. These correlations
introduce a measurable transport asymmetry wholly unrelated to static spin
polarization and external magnetic fields and might in future be used as a
method to probe correlated electron materials.
[1] P. Jacobson _et
al_., _Nature Communications_ **6** , 8536 (2015).
[2] M. Ternes, _New
J. Phys._ **17** , 063016 (2015).
[3] M. Ternes, _Prog.
Surf. Sci._ **92** , 83 (2017).
[4] P. Jacobson _et
al_., _Science Advances_ **3** , e1602060 (2017).
[5] M. Muenks, _et al_., _Nature
Communications_ **8** , 14119 (2017).