A5073298366- Quantum and electron transport phenomena
- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Molecular Junctions and Nanostructures
- Surface and Thin Film Phenomena
Charles University
2023-2024
We study the spatiotemporal dynamics of ultrafast electron spin transport across nanometer-thick copper layers using ultrabroadband terahertz emission spectroscopy. Our analysis temporal delays, broadening, and attenuation spin-current pulse reveals ballisticlike propagation peak, approaching Fermi velocity, diffusive features including a significant velocity dispersion. A comparison to frequency-dependent Fick's law identifies diffusion-dominated regime for distances $>2\text{ }\text{...
Thin-film stacks
Abstract Antiferromagnetic CuMnAs thin films have attracted attention since the discovery of manipulation their magnetic structure via electrical, optical, and terahertz pulses, enabling convenient approaches for switching between magnetoresistive states film information storage. However, and, thus, efficiency can be affected by morphology growth defects. In this study, properties are investigated probing asymmetrical growth‐related uniaxial anisotropy electric conductivity contact‐free...
We study femtosecond spin currents through MgO tunneling barriers in CoFeB(2 nm)|MgO($d$)|Pt(2 nm) stacks by terahertz emission spectroscopy. To obtain transport information independent of extrinsic experimental factors, we determine the complex-valued conductance $\tilde{G}_d (\omega)$ layer (thickness d= 0-6 {\AA} over a wide frequency range $(\omega/2\pi=$ 0.5-8 THz). In time $(t)$ domain,$ G_d (t)$ has an instantaneous and delayed component that point to (i) Pt pinholes MgO, (ii)...
Antiferromagnetic CuMnAs thin films have attracted attention since the discovery of manipulation their magnetic structure via electrical, optical, and terahertz pulses electric fields, enabling convenient approaches to switching between magnetoresistive states film for information storage. However, and, thus, efficiency can be affected by morphology growth defects. In this study, we investigate properties probing defect-related uniaxial anisotropy conductivity contact-free transmission...
We study the spatiotemporal dynamics of ultrafast electron spin transport across nanometer-thick copper layers using broadband terahertz spectroscopy. Our analysis temporal delays, broadening and attenuation spin-current pulse revealed ballistic-like propagation peak, approaching Fermi velocity, diffusive features including a significant velocity dispersion. A comparison to frequency-dependent Ficks law identified diffusion-dominated regime for distances larger than 2 nm. The findings lie...