Related papers: Exchange Frequencies in the 2d Wigner crystal
A novel method invented to measure the minute thermodynamic spin magnetization of dilute two dimensional fermions is applied to electrons in a silicon inversion layer. Interplay between the ferromagnetic interaction and disorder enhances…
We study the simple Hamiltonian, $H=-K(S_{1z}^2 +S_{2z}^2)+ \lambda\vec S_1\cdot\vec S_2$, of two, large, coupled spins which are taken equal, each of total spin $s$ with $\lambda$ the exchange coupling constant. The exact ground state of…
We have performed time-resolved resonant x-ray scattering studies in the Lanthanide metal Dy to reveal the dynamic response of the helical order exchange coupling to injection of unpolarized spins. The observed spin dynamics are…
We simulate the properties of magnons in erbium oxide, a noncollinear antiferromagnet, from an effective single-ion Hamiltonian, including exchange and long-range dipolar interactions. We parametrize the crystal field splitting of…
The competition between antiferromagnetic and spin-singlet ground states within quantum spin models and the 1/2-filled band Hubbard model has received intense scrutiny. Here we demonstrate a frustration-induced transition from N\'{e}el…
We study the exchange coupling in small Wigner crystals confined to one-dimensional space. In particular we concentrate on the simplest nontrivial case of two electrons in a box potential and calculate analytically the energy splitting…
We perform unrestricted Hartree-Fock (HF) calculations for electrons in a parabolic quantum dot at zero magnetic field. The crossover from Fermi liquid to Wigner molecule behavior is studied for up to eight electrons and various spin…
A spin-fermion model that captures the charge-transfer properties of Cu-based high critical temperature superconductors is introduced and studied via Monte Carlo simulations. The strong Coulomb repulsion among $d$-electrons in the Cu…
We use quantum Monte Carlo to determine the magnetic and transport properties of coupled square lattice spin and fermionic planes as a model for a metal-insulator interface. Specifically, layers of Ising spins with an intra-layer exchange…
Inelastic neutron scattering reveals strong spin fluctuations with energies as high as 0.4eV in the nearly antiferromagnetic metal Cr$_{0.95}$V$_{0.05}$. The magnetic response is well described by a modified Millis-Monien-Pines function.…
We analyze magnetic phases of monolayers of transition metal dichalcogenides that are two-valley materials with electron-electron interactions. The exchange inter-valley scattering makes two-valley systems less stable to the spin…
The $2d$ Hubbard model with nearest-neighbour hopping on the square lattice and an average of one electron per site is known to undergo an extended crossover from metallic to insulating behavior driven by proliferating antiferromagnetic…
When the Coulomb repulsion between electrons dominates over their kinetic energy, electrons in two dimensional systems were predicted to spontaneously break continuous translation symmetry and form a quantum crystal. Efforts to observe this…
We study the Ruderman-Kittel-Kasuya-Yosida effective exchange interaction between magnetic impurities embedded on the edges of transition-metal dichalcogenide flakes, using a three-orbital tight-binding model. Electronic states lying midgap…
An antiferromagnetically exchange-coupled dimer of single molecule magnets which possesses a large spin tunneling has been investigated. For this system the ground and first excited states are entangled states and the Hamiltonian is…
The performance of multi-electron spin qubits is examined by comparing exchange oscillations in coupled single-electron and multi-electron quantum dots in the same device. Fast (> 1 GHz) exchange oscillations with a quality factor Q > 15…
We present Quantum Monte Carlo simulations of the soft-core bosonic Hubbard model with a ring exchange term K. For values of K which exceed roughly half the on-site repulsion U, the density is a non-monotonic function of the chemical…
Spin dynamics of the square lattice Heisenberg antiferromagnet, \BaMnGeO, is studied by a combination of bulk measurements, neutron diffraction, and inelastic neutron scattering techniques. Easy plane type antiferromagnetic order is…
We study the exchange interaction and the subsequent collective behavior of magnetic impurities embedded in a disordered two-dimensional (2D) helical metal. The exchange coupling follows a statistical distribution whose moments are…
We study the ground state quantum spin fluctuations around the N\'eel ordered state for the one-band ($t,U$) Hubbard model on a site-diluted square lattice. An effective spin Hamiltonian, $H_{\rm s}^{(4)}$, is generated using the canonical…