Physical properties of Ba2Mn2Sb2O single crystals

Abstract

We report both experimental and theoretical investigations of the physical properties of Ba2Mn2Sb2O single crystals. This material exhibits a hexagonal structure with lattice constants: a = 4.7029(15)Å and c = 19.9401(27)Å, as obtained from powder X-ray diffraction measurements, and in agreement with structural optimization through density functional theory (DFT) calculations. The magnetic susceptibility and specific heat show anomalies at TN = 60 K, consistent with antiferromagnetic ordering. However, the magnitude of TN is significantly smaller than the CurieWeiss temperature (|ΘCW| ≈ 560 K), suggesting a magnetic system of reduced dimensionality. The temperature dependence of both the in-plane and out-of-plane resistivity changes from an activated at T > Tx ∼ 200 K to a logarithmic at T < Tx. Correspondingly, the magnetic susceptibility displays a bump at Tx. DFT calculations at the DFT + U level support the experimental observation of an antiferromagnetic ground state.

General theories and features of interfacial thermal transport

“…The modal analysis under the NEGF framework has also been formulated 43 . Integration of NEGF and MD has also been proposed to handle complex structure of interface, where MD is used to simulate the atomic reconstruction and relaxation 44 . Beyond NEGF, other quantum theories based on wave function picture, has been developed to handle interface thermal transport 45 .…”

“…Usually defects will introduce imperfection to the lattice structure, increase the surface roughness, cause additional scatterings to the phonons and then reduce the ITC. While high frequency phonons can be scattered by the lattice mismatch, the defects are able to scatter low frequency phonons and hence reduce the ITC 44 . However, a recently study on the graphene/h-BN interface found an abnormal behavior that defects are able to enhance the ITC 52 .…”

Semiconducting double-dot exchange-only qubit dynamics in the presence of magnetic and charge noises

“…Confinement of electron spins in solid state architectures represents a fruitful platform for universal quantum computation as witnessed by several experimental [1,2,3,4,5,6] and theoretical [7,8,9] proposals. The approaches developed range from quantum dot (QD) [10,2,11] to donor-atom nuclear or electron spins [12,13,14].…”

Laser controlled charge-transfer reaction at low temperatures

“…In parallel, multi-channel quantum-defect theories have been developed that parameterize the short-range atom-ion interactions in terms of boundary conditions for the wavefunctions in conjunction with scattering from the long-range potentials [32][33][34][35][36]. They circumvent the need to explicitly know the short-range potentials by re-placing them with a few short-range parameters.…”

“…They circumvent the need to explicitly know the short-range potentials by re-placing them with a few short-range parameters. Reference [35] observed that as few as three parameters can describe the collisional dynamics over a relatively large range of collisional energies E extending from the ultracold regime to about E/k = 1 K, where k is the Boltzmann constant.…”