Abstract
The S=1/2 spin chain material SrCuO2 doped with 1% S=1 Ni impurities is studied by inelastic neutron scattering. At low temperatures, the spectrum shows a pseudogap Δ≈8 meV, absent in the parent compound, and not related to any structural phase transition. The pseudogap is shown to be a generic feature of quantum spin chains with dilute defects. A simple model based on this idea quantitatively accounts for the experimental data measured in the temperature range from 2 to 300 K, and allows us to represent the momentum-integrated dynamic structure factor in a universal scaling form.
| Original language | English |
|---|---|
| Article number | 067204 |
| Journal | Physical Review Letters |
| Volume | 111 |
| Issue number | 6 |
| DOIs | |
| State | Published - Aug 9 2013 |