Stabilization of U <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>5</mml:mn> <mml:msup> <mml:mi>f</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> configuration in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>UTe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> through U <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>6</mml:mn> <mml:mi>d</mml:mi> </mml:mrow> </mml:math> dimers in the presence of Te2 chains
Denise S. Christovam, Martin Sundermann, Andrea Marino, D. Takegami, Johannes Falke, Paulius Dolmantas, Manuel Harder, H. Gretarsson, B. Keimer, A. Gloskovskii, M. W. Haverkort, Ilya Elfimov, Gertrud Zwicknagl, А. В. Андреев, L. Havela, Mitchell M. Bordelon, E. D. Bauer, P. F. S. Rosa, A. Severing, L. H. Tjeng
Abstract
We investigate the topological superconductor candidate <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:msub> <a:mi>UTe</a:mi> <a:mn>2</a:mn> </a:msub> </a:math> using high-resolution valence-band resonant inelastic x-ray scattering at the U <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:msub> <b:mi>M</b:mi> <b:mrow> <b:mn>4</b:mn> <b:mo>,</b:mo> <b:mn>5</b:mn> </b:mrow> </b:msub> </b:math> edges. We observe atomiclike low-energy excitations that support the correlated nature of this unconventional superconductor. These excitations originate from the U <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"> <c:mrow> <c:mn>5</c:mn> <c:msup> <c:mi>f</c:mi> <c:mn>2</c:mn> </c:msup> </c:mrow> </c:math> configuration, which is unexpected since the short Te2-Te2 distances exclude Te2 being <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mn>2</d:mn> <d:mo>−</d:mo> </d:math> . By utilizing the photoionization cross-section dependence of the photoemission spectra in combination with band structure calculations, we infer that the stabilization of the U <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"> <e:mrow> <e:mn>5</e:mn> <e:msup> <e:mi>f</e:mi> <e:mn>2</e:mn> </e:msup> </e:mrow> </e:math> configuration is due to the U <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"> <f:mrow> <f:mn>6</f:mn> <f:mi>d</f:mi> </f:mrow> </f:math> bonding states in the U dimers acting as a charge reservoir. Our results emphasize that the description of the physical properties should commence with a <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"> <g:mrow> <g:mn>5</g:mn> <g:msup> <g:mi>f</g:mi> <g:mn>2</g:mn> </g:msup> </g:mrow> </g:math> ansatz. Published by the American Physical Society 2024