Effect of doping on the pseudogap behaviour and the related terahertz modes in the hybrid chain-ladder compound, Sr14Cu24O41

• Published in: Physics letters. A 2021-08, Vol.408, p.127489, Article 127489
• Main Authors: Hazra, Soumitra, Bag, Rabindranath, Singh, Surjeet, Kini, Rajeev N.
• Format: Article
• Language: English
• Subjects: Charge density wave systems; Collective modes; Cuprates; Hole pairing; Spin-ladder compounds; Terahertz spectroscopy
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2021.127489

•Observation of a pseudogap behaviour in the hybrid chain-ladder compound, Sr14Cu24O41.•The effect of doping with Co and Al on the pseudogap behaviour and the related THz modes in Sr14Cu24O41 is investigated.•Doping dependence studies show that the pseudogap behaviour is due to the ordered arrangement of holes in the ladders. Using Terahertz (THz) spectroscopy, we report the observation of a pseudogap behaviour in the hybrid chain-ladder compound Sr14Cu24O41 (SCO). This is possibly due to the ordered arrangement of hole pairs in SCO's ladder plane, below the transition temperature, Tco. Several optical modes in the THz frequency range between 60 cm−1 and 90 cm−1, similar to those reported earlier, was also observed. We find that the pseudogap behaviour and the THz-active modes are strongly affected by doping with 5% Co and 0.25% Al, but the effect of 1% Co is not as much. These differences are discussed in terms of the location of these dopants in the chain and ladder substructures.