Low-Lying Excited States and Low-Temperature Properties of an Alternating Spin-1 / Spin-1/2 Chain : A DMRG study

Abstract

We report spin wave and DMRG studies of the ground and low-lying excited states of uniform and dimerized alternating spin chains. The DMRG procedure is also employed to obtain low-temperature thermodynamic properties of the system. The ground state of a 2N spin system with spin-1 and spin-1/2 alternating from site to site and interacting via an antiferromagnetic exchange is found to be ferrimagnetic with total spin $s_G=N/2$ from both DMRG and spin wave analysis. Both the studies also show that there is a gapless excitation to a state with spin $s_G-1$ and a gapped excitation to a state with spin $s_G+1$. Surprisingly, the correlation length in the ground state is found to be very small from both the studies for this gapless system. For this very reason, we show that the ground state can be described by a variational ``ansatz'' of the product type. DMRG analysis shows that the chain is susceptible to a conditional spin-Peierls' instability. The DMRG studies of magnetization, magnetic susceptibility ($\chi$) and specific heat show strong magnetic-field dependence. The product $\chi T$ shows a minimum as a function of temperature($T$) at low-magnetic fields and the minimum vanishes at high-magnetic fields. This low-field behaviour is in agreement with earlier experimental observations. The specific heat shows a maximum as a function of temperature and the height of the maximum increases sharply at high magnetic fields. It is hoped that these studies will motivate experimental studies at high-magnetic fields.

22 pages in latex; 16 eps figures available upon request

References in corpus (12)

• Surprises on the Way from 1D to 2D Quantum Magnets: the Novel Ladder Materials
• DMRG Studies of the Spin-Half Heisenberg System with Dimerization and Frustration
• Impurities in S=1/2 Heisenberg Antiferromagnetic Chains: Consequences for Neutron Scattering and Knight Shift
• Matrix product states approach to the Heisenberg ferrimagnetic spin chains
• Equal Time Correlations in Haldane Gap Antiferromagnets
• Density Matrix Renormalization Group Applied to the Ground State of the XY-Spin-Peierls System
• Numerical renormalization group study of the correlation functions of the antiferromagnetic spin-$\frac{1}{2}$ Heisenberg chain
• Excitation Spectrum of $S=1$ Antiferromagnetic Chains
• Density matrix renormalisation group study of the correlation function of the bilinear-biquadratic spin-1 chain
• Numerical Renormalization Group Study of Pseudo-Fermion and Slave-Boson Spectral Functions in the Single Impurity Anderson Model
• Density Matrix Renormalization Group Method for the Random Quantum One-Dimensional Systems - Application to the Random Spin-1/2 Antiferromagnetic Heisenberg Chain -
• Phase Diagram of the Spin-One Heisenberg System with Dimerization and Frustration

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