Are topological Hall signals in thin films evidence of skyrmions? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Are topological Hall signals in thin films evidence of skyrmions?
Plain
Skyrmions should deflect electrons and add a bump to the Hall voltage, called the topological Hall effect. Many reported bumps in thin films can also come from two magnetic layers or regions with opposite ordinary anomalous Hall signals, so they may not prove skyrmions exist.
Precise · changed · core
Revision 1: For films and heterostructures (SrRuO3-based, Mn-based, magnetic topological insulators) with reported humps in $\rho_{xy}(H)$, determine for each whether the hump follows $\rho_{TH} \sim P R_0 n_{sk} \Phi_0$ ($P$ spin polarization, $R_0$ ordinary Hall coefficient, $n_{sk}$ skyrmion density, $\Phi_0$ flux quantum) or arises from superposed anomalous Hall loops of opposite sign. An answer is a criterion that separates the two and its application with direct imaging of $n_{sk}$.
Revision 2: For films and heterostructures ($\mathrm{SrRuO_3}$-based, Mn-based, magnetic topological insulators) with reported humps in $\rho_{xy}(H)$, determine for each whether the hump follows $\rho_{TH} \sim P R_0 n_{sk} \Phi_0$ ($P$ spin polarization, $R_0$ ordinary Hall coefficient, $n_{sk}$ skyrmion density, $\Phi_0$ flux quantum) or arises from superposed anomalous Hall loops of opposite sign. An answer is a criterion that separates the two and its application with direct imaging of $n_{sk}$.
Settled by
Simultaneous Hall transport and real-space magnetic imaging (Lorentz electron microscopy, magnetic force microscopy or NV magnetometry) on the same device across the field range of the hump.
Kind
phenomenon
Answer type
classification
References
(empty)
Literature status
contested
Status note
(empty)
Posed since
(empty)

Decisions