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Microscopic model of spin flip-flop processes in crystals doped by rare-earth ions

Syed, Hafsa LU ; Kinos, Adam LU ; Shi, Chunyan LU ; Rippe, Lars LU and Kröll, Stefan LU (2022) In Physical Review B 106(18).
Abstract

Flip-flop processes due to magnetic dipole-dipole interaction between neighboring ions in crystals doped by rare-earth ions are one of the mechanisms of relaxation between hyperfine levels. Modeling of this mechanism has so far been macroscopic, characterized by an average rate describing the relaxation of all ions. Here, however, we present a microscopic model of flip-flop interactions between individual nuclear spins of dopant ions. Every ion is situated in a unique local environment in the crystal, where each ion has different distances and a unique orientation relative to its nearest neighbors, as determined by the lattice structure. Thus each ion has a unique flip-flop rate and the collective relaxation dynamics of all ions in a... (More)

Flip-flop processes due to magnetic dipole-dipole interaction between neighboring ions in crystals doped by rare-earth ions are one of the mechanisms of relaxation between hyperfine levels. Modeling of this mechanism has so far been macroscopic, characterized by an average rate describing the relaxation of all ions. Here, however, we present a microscopic model of flip-flop interactions between individual nuclear spins of dopant ions. Every ion is situated in a unique local environment in the crystal, where each ion has different distances and a unique orientation relative to its nearest neighbors, as determined by the lattice structure. Thus each ion has a unique flip-flop rate and the collective relaxation dynamics of all ions in a bulk crystal is a sum of many exponential decays, giving rise to a distribution of rates rather than a single average decay rate. We employ this model to calculate flip-flop rates in Pr3+:Y2SiO5 and show experimental measurements of population decay of the ground state hyperfine levels at ∼2 K. We also present a method to measure rates of individual transitions from hole burning spectra that requires significantly fewer fitting parameters in theoretical rate equations compared to earlier work. Furthermore, we measure the effect of external magnetic field on the flip-flop rates and observe that the rates slow down by two orders of magnitude in a field of 5-10 mT.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
106
issue
18
article number
184109
publisher
American Physical Society
external identifiers
  • scopus:85143196067
ISSN
2469-9950
DOI
10.1103/PhysRevB.106.184109
language
English
LU publication?
yes
id
2c9bf628-9c62-415b-82ef-88a5455d44bd
date added to LUP
2022-12-23 11:32:26
date last changed
2023-11-19 13:06:52
@article{2c9bf628-9c62-415b-82ef-88a5455d44bd,
  abstract     = {{<p>Flip-flop processes due to magnetic dipole-dipole interaction between neighboring ions in crystals doped by rare-earth ions are one of the mechanisms of relaxation between hyperfine levels. Modeling of this mechanism has so far been macroscopic, characterized by an average rate describing the relaxation of all ions. Here, however, we present a microscopic model of flip-flop interactions between individual nuclear spins of dopant ions. Every ion is situated in a unique local environment in the crystal, where each ion has different distances and a unique orientation relative to its nearest neighbors, as determined by the lattice structure. Thus each ion has a unique flip-flop rate and the collective relaxation dynamics of all ions in a bulk crystal is a sum of many exponential decays, giving rise to a distribution of rates rather than a single average decay rate. We employ this model to calculate flip-flop rates in Pr3+:Y2SiO5 and show experimental measurements of population decay of the ground state hyperfine levels at ∼2 K. We also present a method to measure rates of individual transitions from hole burning spectra that requires significantly fewer fitting parameters in theoretical rate equations compared to earlier work. Furthermore, we measure the effect of external magnetic field on the flip-flop rates and observe that the rates slow down by two orders of magnitude in a field of 5-10 mT.</p>}},
  author       = {{Syed, Hafsa and Kinos, Adam and Shi, Chunyan and Rippe, Lars and Kröll, Stefan}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  number       = {{18}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Microscopic model of spin flip-flop processes in crystals doped by rare-earth ions}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.106.184109}},
  doi          = {{10.1103/PhysRevB.106.184109}},
  volume       = {{106}},
  year         = {{2022}},
}