{"title":"Raman signatures of inversion symmetry breaking structural transition in quasi-1D compound, (TaSe<sub>4</sub>)<sub>3</sub>I.","authors":"Arnab Bera, Partha Sarathi Rana, Suman Kalyan Pradhan, Mainak Palit, Surabhi Saha, Sk Kalimuddin, Satyabrata Bera, Tuhin Debnath, Soham Das, Deep Singha Roy, Subhadeep Datta, Mintu Mondal","doi":"10.1088/1361-648X/ada843","DOIUrl":null,"url":null,"abstract":"<p><p>The breaking of inversion symmetry combined with spin-orbit coupling, can give rise to intriguing quantum phases and collective excitations. Here, we report systematic temperature dependent Raman scattering and theoretical calculations of phonon modes across the inversion symmetry-breaking structural transitions in a quasi-one-dimensional compound (TaSe<sub>4</sub>)<sub>3</sub>I. Our investigation revealed the emergence of three additional Raman-active modes in Raman spectra of the low-temperature non-centrosymmetric (NC) structure of the material. From polarization dependent Raman spectra and phonon mode symmetry analysis, we have identified the origin of these three newly appeared additional Raman-active modes. Notably, two of these modes become Raman active due to the loss of inversion symmetry, while the third mode is identified as a soft phonon mode, arising from the distinctive vibrational motion of tantalum (Ta) atoms along the -Ta-Ta- chains. Furthermore, the temperature evolution of self-energy parameters indicates significant changes in the characteristics of the Raman modes across the transition. Latent heat measurements near the phase transition using Differential Scanning Calorimetry confirm the first-order nature of the transition. Theoretical analysis, including group theory and modeling, reaffirms the displacive first-order nature of the structural transition. Our findings establish (TaSe<sub>4</sub>)<sub>3</sub>I as a model quasi-one-dimensional system with broken inversion symmetry facilitated through a displacive first-order structural transition.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3000,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physics: Condensed Matter","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1361-648X/ada843","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
The breaking of inversion symmetry combined with spin-orbit coupling, can give rise to intriguing quantum phases and collective excitations. Here, we report systematic temperature dependent Raman scattering and theoretical calculations of phonon modes across the inversion symmetry-breaking structural transitions in a quasi-one-dimensional compound (TaSe4)3I. Our investigation revealed the emergence of three additional Raman-active modes in Raman spectra of the low-temperature non-centrosymmetric (NC) structure of the material. From polarization dependent Raman spectra and phonon mode symmetry analysis, we have identified the origin of these three newly appeared additional Raman-active modes. Notably, two of these modes become Raman active due to the loss of inversion symmetry, while the third mode is identified as a soft phonon mode, arising from the distinctive vibrational motion of tantalum (Ta) atoms along the -Ta-Ta- chains. Furthermore, the temperature evolution of self-energy parameters indicates significant changes in the characteristics of the Raman modes across the transition. Latent heat measurements near the phase transition using Differential Scanning Calorimetry confirm the first-order nature of the transition. Theoretical analysis, including group theory and modeling, reaffirms the displacive first-order nature of the structural transition. Our findings establish (TaSe4)3I as a model quasi-one-dimensional system with broken inversion symmetry facilitated through a displacive first-order structural transition.
期刊介绍:
Journal of Physics: Condensed Matter covers the whole of condensed matter physics including soft condensed matter and nanostructures. Papers may report experimental, theoretical and simulation studies. Note that papers must contain fundamental condensed matter science: papers reporting methods of materials preparation or properties of materials without novel condensed matter content will not be accepted.