scholarly journals New Topological Configurations in the Continuous Heisenberg Spin Chain: Lower Bound for the Energy

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Rossen Dandoloff
Keyword(s):  
Lower Bound ◽  
Heisenberg Model ◽  
Unit Vector ◽  
Space Curve ◽  
The Other ◽  
Frenet Frame ◽  
Heisenberg Spin ◽  
One Dimensional ◽  
Heisenberg Spin Chain ◽  
New Class

In order to study the spin configurations of the classical one-dimensional Heisenberg model, we map the normalized unit vector, representing the spin, on a space curve. We show that the total chirality of the configuration is a conserved quantity. If, for example, one end of the space curve is rotated by an angle of 2πrelative to the other, the Frenet frame traces out a noncontractible loop inSO(3)and this defines a new class of topological spin configurations for the Heisenberg model.

Lower Bounds to the Eigenvalues in One-Dimensional Problems by a Shift in the Weight Function

1970 ◽  
Vol 37 (2) ◽  
pp. 267-270 ◽  
Author(s):  
D. Pnueli
Keyword(s):  
Lower Bound ◽  
Weight Function ◽  
Lower Bounds ◽  
Variational Formulation ◽  
Ritz Method ◽  
The Other ◽  
One Dimensional ◽  
Systematic Shift ◽  
The One ◽  
Detailed Computation

A method is presented to obtain both upper and lower bound to eigenvalues when a variational formulation of the problem exists. The method consists of a systematic shift in the weight function. A detailed procedure is offered for one-dimensional problems, which makes improvement of the bounds possible, and which involves the same order of detailed computation as the Rayleigh-Ritz method. The main contribution of this method is that it yields the “other bound;” i.e., the one which cannot be obtained by the Rayleigh-Ritz method.

Grain size effect on magnetic and phase transition features in one-dimensional S = 1/2 Heisenberg spin chain molecular crystals

2015 ◽  
Vol 39 (7) ◽  
pp. 5395-5401 ◽  
Author(s):  
Guo-Jun Yuan ◽  
Yun-Xia Sui ◽  
Jian-Lan Liu ◽  
Xiao-Ming Ren
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Spin Chain ◽  
Molecular Crystals ◽  
Spin Systems ◽  
Grain Size Effect ◽  
Heisenberg Spin ◽  
One Dimensional ◽  
Heisenberg Spin Chain ◽  
Molecular Spin

Magnetic and thermal behaviors and the phase transition nature are strongly influenced by grain size in one-dimensional S = 1/2 molecular spin systems.

PHOTOEMISSION STUDY OF QUASI-ONE-DIMENSIONAL HALOGEN-BRIDGED COMPOUND [Ni(chxn)2Br]Br2

2002 ◽  
Vol 09 (02) ◽  
pp. 1065-1069
Author(s):  
SHIN-ICHI FUJIMORI ◽  
AKIHIRO INO ◽  
TESTUO OKANE ◽  
ATSUSHI FUJIMORI ◽  
KOZO OKADA ◽  
...  
Keyword(s):  
Brillouin Zone ◽  
Spin Chain ◽  
Electron Systems ◽  
Dimensional Electron ◽  
Energy Dispersion ◽  
Heisenberg Spin ◽  
One Dimensional ◽  
Heisenberg Spin Chain ◽  
Photoemission Study

We report results of the angle-resolved photoemission experiments on a quasi-one-dimensional halogen-bridged complex [Ni(chxn) 2 Br]Br 2 ( chxn = 1R, 2R-cyclohexanediamine), which is a one-dimensional Heisenberg spin chain with S = 1/2 and J ~ 3600 K . The expected two dispersions, originated with spin–charge separations as have been observed in other quasi-one-dimensional electron systems like Sr 2 CuO 3, are not clearly observed in this compound. Instead, only one 'band" having about 0.5 eV energy dispersion is found in the half of the Brillouin zone.

scholarly journals Antiferromagnetic Heisenberg Spin Chain of a Few Cold Atoms in a One-Dimensional Trap

2015 ◽  
Vol 115 (21) ◽  
Author(s):  
S. Murmann ◽  
F. Deuretzbacher ◽  
G. Zürn ◽  
J. Bjerlin ◽  
S. M. Reimann ◽  
...  
Keyword(s):  
Spin Chain ◽  
Cold Atoms ◽  
Heisenberg Spin ◽  
One Dimensional ◽  
Heisenberg Spin Chain

GEOMETRIC PHASE IN THE CLASSICAL CONTINUOUS ANTIFERROMAGNETIC HEISENBERG SPIN CHAIN

1990 ◽  
Vol 04 (16) ◽  
pp. 1005-1007 ◽  
Author(s):  
RADHA BALAKRISHNAN ◽  
ALAN R. BISHOP ◽  
ROSSEN DANDOLOFF
Keyword(s):  
Time Evolution ◽  
Spin Chain ◽  
Geometric Phase ◽  
Path Dependence ◽  
Space Curve ◽  
Heisenberg Spin ◽  
Heisenberg Spin Chain

We show that the time evolution of a space curve is associated with a geometric phase. This phase arises from the path dependence of the rotation of the natural Frenet-Serret triad with respect to a nonrotating (Fermi-Walker) frame.

Quantum breathers in XXZ ferromagnetic chains with on-site easy-plane anisotropy

2016 ◽  
Vol 30 (17) ◽  
pp. 1650100 ◽  
Author(s):  
Bing Tang ◽  
De-Jun Li
Keyword(s):  
Magnetic Moment ◽  
Spin Chain ◽  
Easy Plane ◽  
Hartree Approximation ◽  
Heisenberg Spin ◽  
One Dimensional ◽  
Heisenberg Spin Chain ◽  
Plane Anisotropy ◽  
Existence Conditions ◽  
Quantum Breathers

The existence and properties of quantum breathers in a one-dimensional XXZ ferromagnetic Heisenberg spin chain with single-ion easy-plane anisotropy are investigated analytically in the Hartree approximation. We show that the system can support the appearance of quantum breathers, and discuss their existence conditions and properties. In addition, our results show that, for quantum breathers in this system, both the corresponding energy and magnetic moment are quantized.

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