TY  - JOUR
A1  - Schmitt, Martin
A1  - Moras, Paolo
A1  - Bihlmayer, Gustav
A1  - Cotsakis, Ryan
A1  - Vogt, Matthias
A1  - Kemmer, Jeannette
A1  - Belabbes, Abderrezak
A1  - Sheverdyaeva, Polina M.
A1  - Kundu, Asish K.
A1  - Carbone, Carlo
A1  - Blügel, Stefan
A1  - Bode, Matthias
T1  - Indirect chiral magnetic exchange through Dzyaloshinskii–Moriya-enhanced RKKY interactions in manganese oxide chains on Ir(100)
JF  - Nature Communications
N2  - Localized electron spins can couple magnetically via the Ruderman–Kittel–Kasuya–Yosida interaction even if their wave functions lack direct overlap. Theory predicts that spin–orbit scattering leads to a Dzyaloshinskii–Moriya type enhancement of this indirect exchange interaction, giving rise to chiral exchange terms. Here we present a combined spin-polarized scanning tunneling microscopy, angle-resolved photoemission, and density functional theory study of MnO2 chains on Ir(100). Whereas we find antiferromagnetic Mn–Mn coupling along the chain, the inter-chain coupling across the non-magnetic Ir substrate turns out to be chiral with a 120° rotation between adjacent MnO2 chains. Calculations reveal that the Dzyaloshinskii–Moriya interaction results in spin spirals with a periodicity in agreement with experiment. Our findings confirm the existence of indirect chiral magnetic exchange, potentially giving rise to exotic phenomena, such as chiral spin-liquid states in spin ice systems or the emergence of new quasiparticles.
KW  - magnetic properties and materials
KW  - surfaces, interfaces and thin films
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230986
VL  - 10
ER  - 
TY  - JOUR
A1  - Hsu, Pin-Jui
A1  - Kügel, Jens
A1  - Kemmer, Jeannette
A1  - Toldin, Francesco Parisen
A1  - Mauerer, Tobias
A1  - Vogt, Matthias
A1  - Assaad, Fakher
A1  - Bode, Matthias
T1  - Coexistence of charge and ferromagnetic order in fcc Fe
JF  - Nature Communications
N2  - Phase coexistence phenomena have been intensively studied in strongly correlated materials where several ordered states simultaneously occur or compete. Material properties critically depend on external parameters and boundary conditions, where tiny changes result in qualitatively different ground states. However, up to date, phase coexistence phenomena have exclusively been reported for complex compounds composed of multiple elements. Here we show that charge- and magnetically ordered states coexist in double-layer Fe/Rh(001). Scanning tunnelling microscopy and spectroscopy measurements reveal periodic charge-order stripes below a temperature of 130 K. Close to liquid helium temperature, they are superimposed by ferromagnetic domains as observed by spin-polarized scanning tunnelling microscopy. Temperature-dependent measurements reveal a pronounced cross-talk between charge and spin order at the ferromagnetic ordering temperature about 70 K, which is successfully modelled within an effective Ginzburg–Landau ansatz including sixth-order terms. Our results show that subtle balance between structural modifications can lead to competing ordering phenomena.
KW  - ferromagnetism
KW  - phase transitions and critical phenomena
KW  - coexistence
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173969
VL  - 7
ER  -