Observation of the symmetry of core states of a single Fe impurity in GaAs

Bocquel, Juanita; Kortan, VR; Campion, R. P.; Gallagher, B. L.; Flatté, Michael E.; Koenraad, PM Paul

doi:10.1103/physrevb.96.075207

Cited by 3 publications

(11 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These comparisons suggest that there is not the difference present that should exist based on other models [73,74,150] and has been recently observed [119] between the spatial extent of the symmetry split d wavefunctions in this particular spds * tight-binding model. In order to explore this lack of contrast in wavefunction spatial extent it is helpful to examine each symmetry state, d(t 2 ) and d(e), and how it relates to the different tight-binding bonding symmetries, σ, π and δ.…”

Section: Comparison Of Transition Metal Dopants In Diamond and Galliumentioning

confidence: 52%

“…Both tight-binding models [73,74] and density functional theory calculations [150] predict that the d(e) symmetry state will only bond with the host in a limited manner and the dopant wavefunctions will be smaller in spatial extent when compared to those of the d(t 2 ) level. This has been recently shown experimentally for a single iron impurity in gallium arsenide [119]. In a tight-binding model the extent of the wavefunction is governed by the hopping parameters between the host and dopant d levels.…”

Section: Introductionmentioning

confidence: 70%

“…According to the group theory of the T 2 and E irreducible representations, transition metal spin centers with an d(e) symmetry ground state should have a more localized wavefunction than those with d(t 2 ) symmetry ground states. This has been experimentally demonstrated by scanning tunneling microscope measurements of the wavefunction extent for the d(e) and d(t 2 ) levels of an individual iron in gallium arsenide [119]. In principle this could be a strategy for making a quantum memory device.…”

Section: Transition Metal Dopantsmentioning

confidence: 93%

“…However, the localization is still not to the extent as measured by scanning tunneling microscopy [119]. Any comparison of the same transition metal between diamond and gallium arsenide is difficult due to the in general more extended wavefunctions in gallium arsenide.…”

Section: Comparison Of Transition Metal Dopants In Diamond and Galliumentioning

confidence: 99%

“…The set of pd hopping parameters that produce the best contrast for the d(t 2 ) layer of Fe 3 layers above Fe d(e) d(t 2 ) [110] and (c) [112] directions. This measurement was performed in the Koenraad group at the University of Technology in Eindhoven, The Netherlands, and is printed in [119]. The calculated spin averaged real space probability density has been spatially broadened by a factor of 0.12 nm in order to show finer spatial resolution than the measured current.…”

Section: Iron D(e) and D(t 2 ) Wavefunctionsmentioning

confidence: 99%

See 4 more Smart Citations

Transition-metal dopants in tetrahedrally bonded semiconductors

Kortan¹

View full text Add to dashboard Cite

After the birth of my daughter there are a couple people who have facilitated the concurrent raising of an infant and remaining in graduate school all while retaining a semblance of sanity. I thank Amanda for empowering me to make the decisions Adam and I believe are right for our lives, empowering me to be both a mother and myself, and helping me normalize the realities of being a parent. I also thank Miss Sheri and Miss Michele for their humor, their love and their care which has allowed me the luxury of fully applying myself without worry for my child.Lastly I am so grateful for my husband who's steadfast love, emotional support and spelling abilities have allowed this adventure to be a success.iv ABSTRACT It has become increasingly apparent that the future of electronic devices can and will rely on the functionality provided by single or few dopant atoms. The most scalable physical system for quantum technologies, i.e. sensing, communication and computation, are spins in crystal lattices. Diamond is an excellent host crystal offering long room temperature spin coherence times and there has been exceptional experimental work done with the nitrogen vacancy center in diamond demonstrating many forms of spin control. Transition metal dopants have additional advantages, large spin-orbit interaction and internal core levels, that are not present in the nitrogen vacancy center.This work explores the implications of the internal degrees of freedom associated with the core d levels using a tight-binding model and the Koster-Slater technique.The core d levels split into two separate symmetry states in tetrahedral bonding environments and result in two levels with different wavefunction spatial extents. For 4d semiconductors, e.g. GaAs, this is reproduced in the tight-binding model by adding a set of d orbitals on the location of the transition metal impurity and modifying the hopping parameters from impurity to its nearest neighbors. This model does not work in the case of 3d semiconductors, e.g. diamond, where there is no physical reason to drastically alter the hopping from 3d dopant to host and the difference in wavefunction extent is not as pronounced.In the case of iron dopants in gallium arsenide the split symmetry levels in the band gap are responsible for a decrease in tunneling current when measured with a scanning tunneling microscope due to interference between two elastic tunneling paths and comparison between wavefunction measurements and tight-binding calculations provides information regarding material parameters. In the case of transition metal dopants in diamond there is less distinction between the symmetry split d levels.When considering pairs of transition metal dopants an important quantity is v the exchange interaction between the two, which is a measure of how fast a gate can be operated between the pair and how well entanglement can be created. The exchange interaction between pairs of transition metal dopants has been calculated in diamond for several directions in the (110) plane, and for sele...

show abstract

Section: Comparison Of Transition Metal Dopants In Diamond and Galliumentioning

confidence: 52%

Section: Introductionmentioning

confidence: 70%

Section: Transition Metal Dopantsmentioning

confidence: 93%

Section: Comparison Of Transition Metal Dopants In Diamond and Galliumentioning

confidence: 99%

Section: Iron D(e) and D(t 2 ) Wavefunctionsmentioning

confidence: 99%

See 3 more Smart Citations

Transition-metal dopants in tetrahedrally bonded semiconductors

Kortan¹

View full text Add to dashboard Cite

show abstract

Scanning Tunneling Microscopy and Spectroscopy of Semiconductor Materials

Grandidier¹

2018

Reference Module in Materials Science and Materials Engineering

View full text Add to dashboard Cite

High-temperature intrinsic ferromagnetism in heavily Fe-doped GaAs layers

Kudrin

Lesnikov

Danilov

et al. 2020

Semicond. Sci. Technol.

View full text Add to dashboard Cite

The layers of a high-temperature novel GaAs:Fe diluted magnetic semiconductor (DMS) with an average Fe content up to 20 at. % were grown on (001) i-GaAs substrates using a pulsed laser deposition in a vacuum. The transmission electron microscopy (TEM) and energy-dispersive x-ray spectroscopy investigations revealed that the conductive layers obtained at 180 and 200 ºC are epitaxial, do not contain any second-phase inclusions, but contain the Fe-enriched columnar regions of overlapped microtwins. The TEM investigations of the non-conductive layer obtained at 250 ºC revealed the embedded coherent Fe-rich clusters of GaAs:Fe DMS. The x-ray photoelectron spectroscopy investigations showed that Fe atoms form chemical bonds with Ga and As atoms with almost equal probability and thus the comparable number of Fe atoms substitute on Ga and As sites. The n-type conductivity of the obtained conductive GaAs:Fe layers is apparently associated with electron transport in a Fe acceptor impurity band within the GaAs band gap. A hysteretic negative magnetoresistance (MR) was observed in the conductive layers up to room temperature (RT). MR measurements point to the out-of-plane magnetic anisotropy of the conductive GaAs:Fe layers related to the presence of the columnar regions. The studies of the magnetic circular dichroism confirm that the layers obtained at 180, 200 and 250 ºC are intrinsic ferromagnetic semiconductors and the Curie point can reach up to at least RT in case of the conductive layer obtained at 200 ºC. It was suggested that in heavily Fe-doped GaAs layers the ferromagnetism is related to the Zener double exchange between Fe atoms with different valence states via an intermediate As and Ga atom.

show abstract

Observation of the symmetry of core states of a single Fe impurity in GaAs

Cited by 3 publications

References 42 publications

Transition-metal dopants in tetrahedrally bonded semiconductors

Transition-metal dopants in tetrahedrally bonded semiconductors

Scanning Tunneling Microscopy and Spectroscopy of Semiconductor Materials

High-temperature intrinsic ferromagnetism in heavily Fe-doped GaAs layers

Contact Info

Product

Resources

About