The quasi-magnetic-hysteresis behavior of polydisperse ferrofluids with small coupling constant

2012 ◽  
Vol 407 (24) ◽  
pp. 4638-4642 ◽  
Author(s):  
Jian Li ◽  
Yueqiang Lin ◽  
Xiaodong Liu ◽  
Lihua Lin ◽  
Qingmei Zhang ◽  
...  
Keyword(s):  
Magnetic Hysteresis ◽  
Coupling Constant ◽  
Hysteresis Behavior ◽  
Small Coupling ◽  
Small Coupling Constant

Optical properties of complex oxides: Vanadate ladders and related inorganic nanotubes

2002 ◽  
Vol 12 (9) ◽  
pp. 355-355
Author(s):  
J. L. Musfeldt ◽  
A. B. Sushkov ◽  
J. Jegoudez ◽  
A. Revcolevschi ◽  
P. Millet ◽  
...  
Keyword(s):  
Phase Boundary ◽  
Degrees Of Freedom ◽  
Energy Scale ◽  
Coupling Constant ◽  
Field Phase ◽  
Inorganic Nanotubes ◽  
Small Coupling ◽  
Small Coupling Constant ◽  
Na Ions ◽  
T Phase

Optical spectroscopy is a sensitive probe of charge, spin, and lattice degrees of freedom. In this talk, I will detail our magneto-optical work on alpha'-NaV2O5, a prototypical ladder material, as well as the new Na2V3O7 nanotubes. Using changes in electronic structure with temperature and applied magnetic field, we have mapped out the H-T phase diagram of alpha'-NaV2O5. We find a temperature independent phase boundary at 27 T which persists above Tc (34 K), a kink in Tc(H) near 27 T, and H$\wedge $2 behavior of Tc(H) in the high field phase with an unusually small coupling constant. The energy scale of Tc and the newly discovered phase boundary at Hc (27 T) are identical. Confinement effects are investigated in the related nanotubes. Results include a larger gap than in analogous bulk materials as well as a low-energy rattling mode, which corresponds to the motion of Na+ ions inside the nanotube.

scholarly journals Spectral Theory for a Mathematical Model of the Weak Interaction—Part I: The Decay of the Intermediate Vector BosonsW±

2009 ◽  
Vol 2009 ◽  
pp. 1-52 ◽  
Author(s):  
J.-M. Barbaroux ◽  
J.-C. Guillot
Keyword(s):  
Ground State ◽  
State Energy ◽  
Fock Space ◽  
Adjoint Operator ◽  
Weak Decay ◽  
Spectral Interval ◽  
Coupling Constant ◽  
Small Coupling ◽  
Small Coupling Constant ◽  
Intermediate Vector

We consider a Hamiltonian with cutoffs describing the weak decay of spin 1 massive bosons into the full family of leptons. The Hamiltonian is a self-adjoint operator in an appropriate Fock space with a unique ground state. We prove a Mourre estimate and a limiting absorption principle above the ground state energy and below the first threshold for a sufficiently small coupling constant. As a corollary, we prove the absence of eigenvalues and absolute continuity of the energy spectrum in the same spectral interval.

scholarly journals Radiative corrections and instability of large Q-balls

2017 ◽  
Vol 32 (37) ◽  
pp. 1750198 ◽  
Author(s):  
A. V. Kovtun ◽  
E. Ya. Nugaev
Keyword(s):  
The Self ◽  
Radiative Corrections ◽  
Coupling Constant ◽  
Small Coupling ◽  
Classical Stability ◽  
Small Coupling Constant ◽  
Self Consistent ◽  
Stable Solutions ◽  
Charge Formula

We discuss stability of Q-balls interacting with fermions in theory with small coupling constant [Formula: see text]. We argue that for configurations with large global U(1)-charge [Formula: see text], the problem of classical stability becomes more subtle. For example, in model with flat direction there is maximal value of charge for stable solutions with [Formula: see text]. This result may be crucial for the self-consistent consideration of Q-ball evaporation into the fermions. We study the origin of additional instability and discuss possible ways to avoid it.

Structure and Magnetic Properties of a Dinuclear, Doubly Methoxo-Bridged Iron(III) Complex with Tetrahydrosalen as Capping Ligand

1992 ◽  
Vol 47 (12) ◽  
pp. 1681-1686 ◽  
Author(s):  
Peter Baran ◽  
Arnd Böttcher ◽  
Horst Elias ◽  
Wolfgang Haase ◽  
Martina Hüber ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Sodium Methoxide ◽  
Effective Magnetic Moment ◽  
Monoclinic Space Group ◽  
Coupling Constant ◽  
Temperature Dependent ◽  
Neutral Complex ◽  
X Ray ◽  
Small Coupling ◽  
Small Coupling Constant

The reaction of the tetrahydrosalen ligand H2L = N,N′-bis(2-hydroxy-3-t-butyl-5-methylbenzyl)- 1,2-diaminoethane with iron(III) chloride in the presence of sodium methoxide affords a neutral complex of the composition [FeL(OMe)]. Single crystal X-ray analysis of this complex shows dinuclear units, [FeL(OMe)]2 = 1, with two methoxide bridges. Complex 1 crystallizes in the monoclinic space group C 2/c with a = 31.67(1)Å, b = 12.544(4)Å, c = 14.135(5)Å and β = 101.33(1)°. The two edge-sharing FeO4N2-octahedra are distorted and connected by a center of inversion. The iron(III) centers are separated by 3.203 Å and weakly antiferromagnetically coupled (J = —5.7 cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the range 4.2 to 280 K. The effective magnetic moment per iron(III) is µeff = 5.24 μΒ at 280 K. The observed small coupling constant J fits well into the magnetostructural relationship suggested recently by Gorun and Lippard (Inorg. Chem. 30,1625 (1991)).

scholarly journals CHAOS–ORDER TRANSITION IN MATRIX THEORY

1998 ◽  
Vol 13 (31) ◽  
pp. 2481-2493 ◽  
Author(s):  
I. YA. AREF'EVA ◽  
A. S. KOSHELEV ◽  
P. B. MEDVEDEV
Keyword(s):  
Angular Momentum ◽  
Matrix Theory ◽  
Chaotic Behavior ◽  
Order Transition ◽  
Classical Dynamics ◽  
Coupling Constant ◽  
Small Coupling ◽  
Classical Chaos ◽  
Small Coupling Constant

Classical dynamics in SU(2) matrix theory is investigated. A classical chaos–order transition is found. For small enough angular momentum (even for small coupling constant), the system exhibits a chaotic behavior, for large enough angular momentum, the system is regular.

scholarly journals Mass Renormalization in the Nelson Model

2017 ◽  
Vol 2017 ◽  
pp. 1-21 ◽  
Author(s):  
Fumio Hiroshima ◽  
Susumu Osawa
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Field ◽  
Bare Mass ◽  
Coupling Constant ◽  
Mass Renormalization ◽  
Cutoff Parameter ◽  
Nelson Model ◽  
Small Coupling ◽  
Small Coupling Constant

The asymptotic behavior of the effective mass meff(Λ) of the so-called Nelson model in quantum field theory is considered, where Λ is an ultraviolet cutoff parameter of the model. Let m be the bare mass of the model. It is shown that for sufficiently small coupling constant α of the model, meff(Λ)/m can be expanded as meff(Λ)/m=1+∑n=1∞an(Λ)α2n. A physical folklore is that an(Λ)=O(logΛ(n-1)) as Λ→∞. It is rigorously shown that 0<limΛ→∞a1(Λ)<C,  C1≤limΛ→∞a2(Λ)/log⁡Λ≤C2 with some constants C, C1, and C2.

The use of double irradiation methods for the assignment of ABX2 spectra with a very small coupling constant

1970 ◽  
Vol 2 (2) ◽  
pp. 209-215
Author(s):  
D.G de Kowalewski ◽  
R Loesener
Keyword(s):  
Coupling Constant ◽  
Small Coupling ◽  
Small Coupling Constant

Nachweis starker C – Sn-Hyperkonjugation über Kristallstruktur und NMR-Daten eines C-Stannylmethylenborans / Evidence for Strong C–Sn-Hyperconjugation by Crystal Structure and NMR Data of a C-Stannylmethyleneborane

1990 ◽  
Vol 45 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Jürgen Allwohn ◽  
Ralf Hunold ◽  
Monika Pilz ◽  
Rolf-Günter Müller ◽  
Werner Massa ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Carbon Atom ◽  
Boron Atom ◽  
Bond Angle ◽  
Coupling Constant ◽  
Small Coupling ◽  
Nmr Data ◽  
Small Coupling Constant

Strong C—Sn hyperconjugation in C-stannylmethyleneborane 3 is indicated by (1) a small B—sp2C—Sn bond angle (105.6°), (2) a long sp2C—Sn bond (216 pm), (3) a very short B=C double bond (131 pm), (4) a very small coupling constant 1J(119Sn-13C) = 125 Hz for the sp2C—Sn bond and (5) shielding of the boron atom of the B=C double bond by 20 ppm as compared to methyleneboranes without strong hyperconjugation. The boron atoms of the B=C double bond of 3 and related methyleneboranes act as π-donor and σ-acceptor, the substituents X at the carbon atom of the B=C double bond as π-acceptors and, through their C—X σ-bonds, as σ-donors. The partly bridged methyleneborane 3 closes the gap between unbridged and bridged methyleneboranes. Relationships to non-classical carbocations are pointed out.

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