Direct observation of dynamic charge stripes in La2 xSrxNiO4

Journal Article · Wed Jan 01 04:00:00 EST 2014 · Nature Communications

DOI:https://doi.org/10.1038/ncomms4467· OSTI ID:1133593

Anissimova, S. ^[1]; Parshall, D ^[1]; Gu, Genda ^[2]; Marty, K. ^[3]; Lumsden, Mark D ^[4]; Chi, Songxue ^[4]; Fernandez-Baca, Jaime A ^[4]; Abernathy, D. ^[3]; Lamago, D. ^[5]; Tranquada, John M. ^[2]; Reznik, Dmitry ^[1]

---

1. University of Colorado, Boulder
2. Brookhaven National Laboratory (BNL)
3. Oak Ridge National Laboratory (ORNL)
4. ORNL
5. Laboratoire Leon Brillouin, France

The insulator-to-metal transition continues to be a challenging subject, especially when electronic correlations are strong. In layered compounds, such as La2 xSrxNiO4 and La2 xBaxCuO4, the doped charge carriers can segregate into periodically spaced charge stripes separating narrow domains of antiferromagnetic order. Although there have been theoretical proposals of dynamically fluctuating stripes, direct spectroscopic evidence of charge-stripe fluctuations has been lacking. Here we report the detection of critical lattice fluctuations, driven by charge-stripe correlations, in La2 xSrxNiO4 using inelastic neutron scattering. This scattering is detected at large momentum transfers where the magnetic form factor suppresses the spin fluctuation signal. The lattice fluctuations associated with the dynamic charge stripes are narrow in q and broad in energy. They are strongest near the charge-stripe melting temperature. Our results open the way towards the quantitative theory of dynamic stripes and for directly detecting dynamical charge stripes in other strongly correlated systems, including high-temperature superconductors such as La2 xSrxCuO4.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor (HFIR); Spallation Neutron Source
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1133593
• Journal Information: Nature Communications, Journal Name: Nature Communications Vol. 5; ISSN 2041-1723
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English