Observation of the spin-Peierls transition in linearCu2+(spin-1/2) chains in an inorganic compoundCuGeO

Two-gap magnetic structure of the two-stack anion-radical salt (N-Me-3,5-Di-Me-Py)(TCNQ)2 (Py is pyridine)

“…This transition was experimentally observed for the first time in charge-transfer complexes (TTF)[M{S 2 C 2 (CF 3 ) 2 }] (TTF = tetrathiafulvalene) (M = Cu, Au) [6,7] and MEM-(TCNQ) 2 (MEM = methyl-ethylmorpholinium) [8]. Decades later, the spin-Peierls transition was observed also in inorganic compounds, firstly in CuGeO 3 [9], which is a main representant of spinPeierls inorganic systems, and later also in (VO) 2 P 2 O 7 [10], which is a model system of interacting chains. Moreover, in the latter compound two energy gaps were observed [11].…”

The random mass Dirac model and long-range correlations on an integrated optical platform

“…This leads to random walks, with a nonvanishing occurrence of long jumps [3][4][5] , as well as long-range ordering effects in organic and inorganic materials 2,[6][7][8][9] . Spin-1/2 chains with antiferromagnetic interaction, so called the spinPeierls systems 10,11 , as well as cross-coupled spin-1/2 chains, so called the spin-ladder systems 12,13 , are both prime examples of solids with long-range ordered phases. Doping in these materials causes impurity spins, which support low-energy, exponentially localized defect states within the band gap of the host material, but exhibit long-range averaged correlations decaying with a power law over distance.…”

Susceptibility Behaviour of CuGeO3: Comparison between Experiment and the Quantum Transfer Matrix Approach

“…Both experimental and theoretical interest in quasi one-dimensional frustrated quantum spin systems has been strongly enhanced since 1993, when it was shown [1] that the magnetic susceptibility of CuGeO3 measured in all crystal directions drastically drops below TsP = 14.3 K. It was attributed to the spin-Peierls (SP) phase transition, which manifests itself when a system of quasi one-dimensional quantum spin chains undergoes dimerization due to a lattice distortion. Below the SP transition point ΤSP, a finite energy gap Δ opens between the non-magnetic singlet ground state and the first excited triplet state and reaches the maximum value Δ ^ 2.1 meV at Τ = 0 K.…”