{"id":1105,"date":"2020-07-18T14:22:05","date_gmt":"2020-07-18T18:22:05","guid":{"rendered":"http:\/\/girsh.rutgers.edu\/?p=1105"},"modified":"2020-07-21T10:13:17","modified_gmt":"2020-07-21T14:13:17","slug":"critical-charge-fluctuations-and-quantum-coherent-state-in-excitonic-insulator-ta2nise5","status":"publish","type":"post","link":"https:\/\/girsh.rutgers.edu\/index.php\/2020\/07\/18\/critical-charge-fluctuations-and-quantum-coherent-state-in-excitonic-insulator-ta2nise5\/","title":{"rendered":"Critical charge fluctuations and quantum coherent state in excitonic insulator Ta2NiSe5"},"content":{"rendered":"

Pavel A. Volkov,\u00a0Mai Ye,\u00a0Himanshu Lohani,\u00a0Irena Feldman,\u00a0Amit Kanigel,\u00a0Kristjan Haule,\u00a0Girsh Blumberg<\/p>\n

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\n(A) and (B): Raman response \u03c7”aa<\/sub>\u00a0and\u00a0\u03c7”ac<\/sub> in the aa and ac scattering geometries, respectively. (C) and (D): \u03c7”aa<\/sub> and \u03c7”ac<\/sub> in the range enclosed by the dashed white boxes in (A) and (B) on a linear frequency scale.<\/p>\n

Attraction between electrons in metals drives superconductivity – an example of a macroscopic coherent state. In semiconductors, electrons and holes may sustain macroscopic coherence due to Coulomb attraction in another state – the excitonic insulator. With only a few candidate materials known, many of its features can be obscured by structural effects, making the excitonic insulator state challenging to identify. Using polarization-resolved Raman spectroscopy, we reveal critical softening of an excitonic collective mode driving the transition in Ta2<\/sub>NiSe5<\/sub>, and coherent superposition of band states at the gap edge, analogous to coherence factors in a superconductor. The temperature evolution of the spectra reveals departures from mean-field theory predictions, pointing to a unified view of Ta2<\/sub>NiSe5<\/sub> as a strongly correlated exciton insulator.<\/p>\n

Read more on arXiv:2007.07344.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Pavel A. Volkov,\u00a0Mai Ye,\u00a0Himanshu Lohani,\u00a0Irena Feldman,\u00a0Amit Kanigel,\u00a0Kristjan Haule,\u00a0Girsh Blumberg (A) and (B): Raman response \u03c7”aa\u00a0and\u00a0\u03c7”ac in the aa and ac scattering geometries, respectively. (C) and (D): \u03c7”aa and \u03c7”ac in the range enclosed by the dashed white boxes in (A) and (B) on a linear frequency scale. Attraction between electrons in metals drives superconductivity – …<\/p>\n

Critical charge fluctuations and quantum coherent state in excitonic insulator Ta2NiSe5<\/span> Read More »<\/a><\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/posts\/1105"}],"collection":[{"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/comments?post=1105"}],"version-history":[{"count":15,"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/posts\/1105\/revisions"}],"predecessor-version":[{"id":2086,"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/posts\/1105\/revisions\/2086"}],"wp:attachment":[{"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/media?parent=1105"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/categories?post=1105"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/girsh.rutgers.edu\/index.php\/wp-json\/wp\/v2\/tags?post=1105"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}