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  >>> Topics >>> Quasiparticles in Quasi-1D Quantum Spin Systems
 
Generation and manipulation of nonlocal entangled electrons
Physics of Intrinsic Josephson Junctions and Terahertz Emission
Quasiparticles in
Quasi-1D Quantum Spin Systems
Novel Functional Materials for Spintronics
Physics of Vortex Matter in Type II Superconductors

 

 

In the absence of a magnetic field, it is known that dynamical properties of the spin-1/2 antiferromagnetic Heisenberg chain are characterized by spinons (quasiparticles carrying fractional quantum numbers) rather than conventional magnons (quasiparticles carrying integer quantum numbers).

In the presence of a magnetic field, it is also known that quasiparticles similar to spinons, called psinons and anti-psinons, well explain characteristic behaviors of dynamical structure factors Szz(k,��) and S-+(k,��). However, a large part of spectral weights in S+-(k,��) has remained unexplained in terms of these quasiparticles.

We investigated dynamical properties of the Heisenberg chain in a magnetic field, using exact Bethe-ansatz solutions. We took into account solutions with complex rapidities, called string solutions, and found that they have considerable spectral weights in S+-(k,��). In particular, we found that solutions with a string of length 2 (2-string) form a well-defined continuum that connects the mode of low-lying excitations in the zero-field limit and the mode of bound states of overturned spins from the fully polarized state near the saturation field. This implies that not only psinons and anti-psinons but also the quasiparticle representing the 2-string plays an important role for dynamical properties of 1D spin chains in a magnetic field.


Figure: Dynamical structure factorsS+-(k,��),Szz(k,��), andS-+(k,��) of the spin-1/2 antiferromagnetic Heisenberg chain in a magnetic field, calculated using exact Bethe-ansatz solutions.

For more details, please refer to the attached pdf file

 

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