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Updated: Jun 14, 2025
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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
9.9K
Heisenberg spin chain with random-sign couplings
Michele Fava1, Jesper Lykke Jacobsen2,3, Adam Nahum2
1Physics Department, École Normale Supérieure, Philippe Meyer Institute, Université Paris Science et Lettres, Paris F-75231, France.
Summary
This study reveals that 1D quantum Heisenberg chains with random couplings exhibit spin glass order for large spins. Spin waves in this system show intermediate dynamics between ferromagnetic and antiferromagnetic behavior.
Area of Science:
- Condensed Matter Physics
- Quantum Magnetism
- Disordered Systems
Background:
- The 1D quantum Heisenberg chain with random couplings is a key model in condensed matter physics.
- Previous studies utilized approximate strong-disorder renormalization group (RG) methods.
Purpose of the Study:
- To investigate the ground state properties and spin wave dynamics of the 1D quantum Heisenberg chain with random ferromagnetic and antiferromagnetic couplings.
- To compare analytical results with numerical simulations.
Main Methods:
- Analytical techniques, including the renormalization group (RG) approach.
- Density matrix renormalization group (DMRG) simulations for numerical validation.
Main Results:
- The ground state exhibits "spin glass" order for sufficiently large spin quantum number (S).
- Spin waves possess a dynamical exponent (z) intermediate between 1 (antiferromagnet) and 2 (ferromagnet).
- DMRG simulations align well with analytical findings for S = 1 and S = 1/2, with potential for small ordered moments in the S = 1/2 case.
Conclusions:
- The 1D quantum Heisenberg chain with random couplings displays complex magnetic ordering.
- The system's behavior is characterized by spin glass order and unique spin wave dynamics.
- Numerical and analytical methods confirm the theoretical predictions, highlighting the importance of spin quantum number S.
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