Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2608.03128

Apparent Dresselhaus coefficient in (001) GaAs quantum wells: Correlation-time renormalization in D'yakonov-Perel' spin relaxation

Yuzo Ohno·Jun Ishihara·Satoshi Iba
View original source ↗Read source document ↗Export metadata ↓

Abstract

We study the Dresselhaus coefficient inferred from D'yakonov-Perel' spin relaxation in bulk GaAs and (001) GaAs quantum wells using nonballistic Monte Carlo simulations. In bulk GaAs, inelastic LO-phonon simulations reproduce the spin relaxation with a cubic Dresselhaus coefficient γ_{3D}\simeq12.4 eVÅ^3 and a cubic-field correlation time τ_3^{3D}\simeq150 fs. In a projected two-dimensional quantum-well model, however, k_z^2 is replaced by the static expectation value \langle k_z^2 \rangle, converting the dominant Dresselhaus field into a term linear in the in-plane wave vector. We show that this projection changes the D'yakonov-Perel' correlation kernel from K_3^{2D} to a first- and third-order hybridized kernel K_{1+3}^{2D}, for which the correlation time τ_{1+3}^{2D} approaches 235 fs in the strict two-dimensional limit, in contrast to the third-order correlation time τ_3^{2D} of 130 fs. Consequently, the coefficient entering the projected two-dimensional model is not the intrinsic cubic coefficient itself but an apparent coefficient, γ_{2D}^{app}=γ_{3D} \sqrt{τ_3^{2D}/τ_{1+3}^{2D}}. Since τ_{1+3}^{2D}\simeq1.8τ_3^{2D} under LO-phonon-dominated scattering, γ_{2D}^{app}\simeq9.2 eVÅ^3, consistent with spin relaxation in (001) GaAs quantum wells. This correlation-time renormalization clarifies why Dresselhaus coefficients extracted from two-dimensional spin relaxation can differ from the cubic bulk coefficient and provides a useful framework for interpreting linear and cubic Dresselhaus parameters in quantum wells.

Explore related subjects

cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yuzo Ohno, Jun Ishihara, Satoshi Iba. 2026-08-04. Apparent Dresselhaus coefficient in (001) GaAs quantum wells: Correlation-time renormalization in D'yakonov-Perel' spin relaxation. https://arxiv.org/abs/2608.03128

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Incommensurate structural and magnetic modulations in potassium-rich cryptomelane, K$_x$Mn$_8$O$_{16}$ ($x\approx1.45$)

Cryptomelane is a hollandite-like material consisting of K$^+$ cations in an $α$-MnO$_2$ tunnel-like crystallographic motif. Cryptomelane with stoichiometry K$_x$Mn$_8$O$_{16}$ ($x\approx1.45$) has been synthesized and its magnetic properties investigated using variable-temperature magnetic susceptibility, heat capacity, and neutron powder diffraction. Three distinct transitions at $T_1=184$\,K, $T_2=54.5$\,K, and $T_3=24$\,K are observed. At $T_1$ there is a subtle tetragonal$\rightarrow$monoclinic transition associated with emergence of a set of non-magnetic superstructure peaks indexable to a $\vec{k}_\mathrm{struc}\approx0.74\vec{c^*}$ incommensurate modulation parallel to the $α$-MnO$_2$ tunnels. Our findings are consistent with a relation previously reported in titanate hollandites, that $x\approx2|\vec{k}_\mathrm{struc}|$. Magnetic Bragg peaks emerge below $T_2=54.5$\,K, and their positions indicate an incommensurate modulated magnetic structure. The model consistent with the data is a dual-$\vec{k}_\mathrm{mag}$ structure with a ferromagnetic $|\vec{k}_\mathrm{mag}|=0$ component and an incommensurate $\vec{k}_\mathrm{mag}\approx0.37\vec{c^*}$, with the latter most likely to be helical. The period of oscillation of the incommensurate magnetic component is in line with predictions based on a Heisenberg spin Hamiltonian [Mandal \textit{et al}. Phys. Rev. B 90, 104420 (2014)]. Below $T_3=24$\,K, there is a magnetic transition, which gives rise to a different set of magnetic Bragg peaks indicative of a highly complex magnetic structure.

cond-mat.mtrl-sci↗
arXiv2026

An anisotropic functional for two-dimensional material systems

Density function theory is the workhorse of modern electronic structure theory. However, its accuracy in practical calculations is limited by the choice of the exchange-correlation potential. In this respect, two-dimensional materials pose a special challenge, as all these materials and their heterostructures have a crucial similarity. The underlying atomic structures are strongly spatially inhomogeneous, implying that current exchange-correlation functionals, that in almost all cases are isotropic, are ill-prepared for an accurate description. We present an anisotropic screened-exchange potential, that remedies this problem and reproduces the band-gap of 2D materials as well as the piecewise linearity of the total energy with fractional occupation number.

cond-mat.mtrl-sci↗
arXiv2026

Thermally-driven reorientation of the Néel vector in altermagnetic MnTe

Altermagnets are novel magnetic systems that possess a spin-polarized electronic band structure without a net magnetic moment, making them promising for device applications. Hexagonal MnTe, a prototypical altermagnet, arguably exhibits the most properties consistent with theoretical predictions, including an anomalous Hall effect despite a vanishing net magnetization, and altermagnetinduced electronic band splitting. However, fundamental questions remain, including why some effects only appear significantly below the magnetic ordering temperature. Here, we resolve this discrepancy by revealing a reorientation of the Néel vector in single-crystalline MnTe. The Néel vector points 30° from the a-axis at low $T$, before aligning directly with the a-axis around $T\simeq 260$ K. We attribute this to single-ion anisotropy, which depends on temperature-dependent lattice parameters. We obtained these results using muon-spin spectroscopy, magnetization measurements, and X-ray diffraction; we show that the findings are consistent with neutron diffraction. Manipulating this effect, for example through strain, could unlock sensitive electronic detection schemes for external stimuli, paving the way for functional altermagnetic devices.

cond-mat.mtrl-sci↗