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Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
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Dynamical Negative Differential Resistance in Antiferromagnetically Coupled Few-Atom Spin Chains.
Steffen Rolf-Pissarczyk1,2, Shichao Yan1,2,3, Luigi Malavolti1,2
1Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany.
Physical Review Letters
|December 9, 2017
Summary
Negative differential resistance (NDR) emerges in spin-dependent electron transport through a few-atom spin chain. This phenomenon is linked to inelastic tunneling dynamically locking atomic spins, impacting magnetoresistance and quenching elastic tunneling.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Materials science
Background:
- Spin-dependent electron transport is crucial for spintronic devices.
- Understanding electron behavior in few-atom magnetic chains is key for novel electronic functionalities.
- Negative differential resistance (NDR) is a desirable property for advanced electronic circuits.
Purpose of the Study:
- To investigate the appearance of NDR in spin-dependent electron transport.
- To explore the role of atomic spin dynamics in transport properties.
- To understand the interplay between dynamic spin locking and magnetic exchange interactions.
Main Methods:
- Fabrication of a few-atom spin chain (Fe trimer) on a Cu2N/Cu(100) surface.
- Utilizing a spin-polarized scanning tunneling microscope tip for controlled coupling.
- Measuring electron transport properties at low bias voltages.
Main Results:
- Observed pronounced NDR at a low bias of 7 mV.
- Demonstrated that inelastic electron tunneling dynamically locks the atomic spin into an excited state.
- Showed that this dynamic locking increases magnetoresistance and quenches elastic tunneling.
- Found that varying tip-trimer coupling strength reveals competition between dynamic locking and static magnetic exchange interactions.
Conclusions:
- NDR in few-atom spin chains is achievable and controllable.
- The observed NDR is driven by the dynamic locking of atomic spins via inelastic electron tunneling.
- The interplay between dynamic and static magnetic interactions dictates the transport properties and the presence of NDR.
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