Competitive superconductivity and charge density wave in Mo-doped kagome superconductor CsV3Sb5

In the kagome superconductors <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi>A</a:mi><a:msub><a:mi mathvariant="normal">V</a:mi><a:mn>3</a:mn></a:msub><a:mi mathvariant="normal">S</a:mi><a:msub><a:mi mathvariant="normal">b</a:mi><a:mn>5</a:mn></a:msub></a:mrow></a:math> (<e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:mi>A</e:mi></e:mrow></e:math> = K, Rb, Cs), understanding the charge-density-wave (CDW) state and its entanglement with the superconducting ground state is still a challenging issue. Here, by measuring the electrical transport, magnetic susceptibility, Hall effect, and <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mmultiscripts><f:mi mathvariant="normal">V</f:mi><f:mprescripts/><f:none/><f:mn>51</f:mn></f:mmultiscripts></f:math> nuclear magnetic resonance (NMR), the evolution of superconductivity (SC) and the CDW is comprehensively studied in <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:mrow><h:mi>Cs</h:mi><h:msub><h:mrow><h:mo>(</h:mo><h:mrow><h:msub><h:mi mathvariant="normal">V</h:mi><h:mrow><h:mn>1</h:mn><h:mo>−</h:mo><h:mi>x</h:mi></h:mrow></h:msub><h:mi mathvariant="normal">M</h:mi><h:msub><h:mi mathvariant="normal">o</h:mi><h:mi>x</h:mi></h:msub></h:mrow><h:mo>)</h:mo></h:mrow><h:mn>3</h:mn></h:msub><h:mi mathvariant="normal">S</h:mi><h:msub><h:mi mathvariant="normal">b</h:mi><h:mn>5</h:mn></h:msub></h:mrow></h:math>. In contrast with previously reported results for other doped cases, the CDW transition temperature slightly increases to ∼100 K with increasing Mo doping. Meanwhile, the SC is quickly suppressed and vanishes above <n:math xmlns:n="http://www.w3.org/1998/Math/MathML"><n:mrow><n:mi>x</n:mi><n:mo>=</n:mo><n:mn>0.02</n:mn></n:mrow></n:math>. The anomalous Hall effect (AHE), which is tied to the exotic nature of the CDW state in pristine <o:math xmlns:o="http://www.w3.org/1998/Math/MathML"><o:mrow><o:mi>Cs</o:mi><o:msub><o:mi mathvariant="normal">V</o:mi><o:mn>3</o:mn></o:msub><o:mi mathvariant="normal">S</o:mi><o:msub><o:mi mathvariant="normal">b</o:mi><o:mn>5</o:mn></o:msub></o:mrow></o:math>, is also strongly suppressed and completely disappears above <s:math xmlns:s="http://www.w3.org/1998/Math/MathML"><s:mrow><s:mi>x</s:mi><s:mo>=</s:mo><s:mn>0.07</s:mn></s:mrow></s:math>. Further <t:math xmlns:t="http://www.w3.org/1998/Math/MathML"><t:mmultiscripts><t:mi mathvariant="normal">V</t:mi><t:mprescripts/><t:none/><t:mn>51</t:mn></t:mmultiscripts></t:math> NMR investigation on the CDW state in <v:math xmlns:v="http://www.w3.org/1998/Math/MathML"><v:mrow><v:mi>Cs</v:mi><v:msub><v:mrow><v:mo>(</v:mo><v:mrow><v:msub><v:mi mathvariant="normal">V</v:mi><v:mrow><v:mn>0.95</v:mn></v:mrow></v:msub><v:mi mathvariant="normal">M</v:mi><v:msub><v:mi mathvariant="normal">o</v:mi><v:mrow><v:mn>0.05</v:mn></v:mrow></v:msub></v:mrow><v:mo>)</v:mo></v:mrow><v:mn>3</v:mn></v:msub><v:mi mathvariant="normal">S</v:mi><v:msub><v:mi mathvariant="normal">b</v:mi><v:mn>5</v:mn></v:msub></v:mrow></v:math> indicates that a short-range stripelike CDW evolves from the original triple-<bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML"><bb:mrow><bb:mi>Q</bb:mi></bb:mrow></bb:math> CDW state with increasing Mo doping, which largely reduces the density of states at the Fermi level. This result provides a self-consistent explanation for the disappearance of both SC and the AHE by increasing Mo doping, which offers insights into the competitive behavior between SC and the CDW state in the kagome superconductors <cb:math xmlns:cb="http://www.w3.org/1998/Math/MathML"><cb:mrow><cb:mi>A</cb:mi><cb:msub><cb:mi mathvariant="normal">V</cb:mi><cb:mn>3</cb:mn></cb:msub><cb:mi mathvariant="normal">S</cb:mi><cb:msub><cb:mi mathvariant="normal">b</cb:mi><cb:mn>5</cb:mn></cb:msub></cb:mrow></cb:math>. Published by the American Physical Society 2024