Inelastic Light Scattering Studies of Quantum Phase Transitions in Copper Titanium Diselenium and Multiferroic Terbium Manganese Trioxygen

Barath, Harini

Permalink

https://hdl.handle.net/2142/80630 Copy

Description

Title

Inelastic Light Scattering Studies of Quantum Phase Transitions in Copper Titanium Diselenium and Multiferroic Terbium Manganese Trioxygen

Author(s)

Barath, Harini

Issue Date

2010

Doctoral Committee Chair(s)

Abbamonte, Peter M.

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Physics, Condensed Matter

Language

eng

Abstract

The second focus of this dissertation is the study of quantum phase transitions in TiSe2 as a function of temperature and Cu-intercalation, and the comparison of the effects of intercalation and pressure on the charge-density-wave (CDW) order in this system. All these parameters---temperature, pressure and Cu-intercalation---suppress the CDW state in TiSe2. Our Raman measurements on CuxTiSe2 show that the x-dependent mode softening exhibits identical scaling behavior to thermal mode softening in undoped TiSe2, suggesting that, like thermal mode softening, the x-dependent mode softening is also associated with a critical point. The softening and significant linewidth broadening of the observed CDW amplitude modes indicate strong fluctuations of the CDW. Even more interesting is the emergence of a superconducting (SC) phase---in CuxTiSe2 and pressure-tuned TiSe 2---indicating a likely coexistence of fluctuating CDW and SC phases near the quantum phase boundary.

Graduation Semester

2010

Type of Resource

text

Permalink

http://hdl.handle.net/2142/80630

Owning Collections