Unexpected magnetic phase in the weakly ordered spin- 12 chain cuprate Sr2CuO3
| Autor: | Igor Zaliznyak, S. S. Sosin, Denis Gorbunov, E. G. Sergeicheva, G. D. Gu, Sergei Zherlitsyn |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed matter physics Resonance Order (ring theory) 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Magnetic field Phase (matter) 0103 physical sciences Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Cuprate 010306 general physics 0210 nano-technology Spin (physics) Excitation |
| Zdroj: | Physical Review B. 101 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | The magnetic phase diagram of a spin-$\frac{1}{2}$ chain antiferromagnet ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{3}$ is studied by an ultrasound phase-sensitive detection technique. The system is in the extreme proximity of the Luttinger-liquid quantum-critical point and we observe an unusually strong effect of magnetic field, which is very weak compared to the in-chain interaction, on the N\'eel ordering temperature. Inside the ordered phase, we detect an unexpected, field-induced continuous phase transition. The transition is accompanied by softening of magnetic excitation observed by electron-spin resonance, which in previous work [E. G. Sergeicheva et al., Phys. Rev. B 95, 020411(R) (2017)] was associated with a longitudinal (amplitude) mode of the order parameter. These results suggest a transition from a transverse collinear antiferromagnet to an amplitude-modulated spin-density-wave phase in a very weak magnetic field, which is unexpected for a system of weakly coupled Heisenberg spin-$\frac{1}{2}$ chains. |
| Databáze: | OpenAIRE |
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