Contrasting impurity-induced magnetism and dynamics in 2 H − MoTe 2

This is the authors' abstract. We don't add key points for this paper.

We investigate the behavior of interstitial <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mmultiscripts> <a:mi>Li</a:mi> <a:none/> <a:mo>+</a:mo> <a:mprescripts/> <a:none/> <a:mn>8</a:mn> </a:mmultiscripts> </a:math> implanted near the surface of <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:mrow> <b:mn>2</b:mn> <b:mi>H</b:mi> <b:mtext>−</b:mtext> <b:msub> <b:mi>MoTe</b:mi> <b:mn>2</b:mn> </b:msub> </b:mrow> </b:math> using <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"> <c:mi>β</c:mi> </c:math> -detected nuclear magnetic resonance. We find that, unlike the muon, <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mmultiscripts> <d:mi>Li</d:mi> <d:none/> <d:mo>+</d:mo> <d:mprescripts/> <d:none/> <d:mn>8</d:mn> </d:mmultiscripts> </d:math> does not show any signature of induced magnetism. This result is consistent with density functional theory, which identifies the Li stopping site at the 2a Wyckoff position in the van der Waals gap and confirms the absence of detectable Li-induced electronic spin polarization. Both the spin-lattice relaxation and the resonance line shape show evidence of pronounced spin dynamics above <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"> <e:mrow> <e:mo>∼</e:mo> <e:mn>200</e:mn> <e:mspace width="0.16em"/> <e:mi mathvariant="normal">K</e:mi> </e:mrow> </e:math> , reminiscent of local stochastic <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"> <h:mmultiscripts> <h:mi>Li</h:mi> <h:none/> <h:mo>+</h:mo> <h:mprescripts/> <h:none/> <h:mn>8</h:mn> </h:mmultiscripts> </h:math> motion within a cage. The resonance line shape consists of quadrupolar satellites on top of a broad central peak. To better understand the interaction of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"> <i:mmultiscripts> <i:mi>Li</i:mi> <i:none/> <i:mo>+</i:mo> <i:mprescripts/> <i:none/> <i:mn>8</i:mn> </i:mmultiscripts> </i:math> with the host material, we employ a frequency-comb measurement by simultaneously exciting four frequencies corresponding to the first-order quadrupolar satellite transitions, <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"> <j:mrow> <j:msub> <j:mi>ν</j:mi> <j:mn>0</j:mn> </j:msub> <j:mo>±</j:mo> <j:mn>3</j:mn> <j:msub> <j:mi>ν</j:mi> <j:mi>comb</j:mi> </j:msub> </j:mrow> </j:math> and <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"> <k:mrow> <k:msub> <k:mi>ν</k:mi> <k:mn>0</k:mn> </k:msub> <k:mo>±</k:mo> <k:msub> <k:mi>ν</k:mi> <k:mi>comb</k:mi> </k:msub> </k:mrow> </k:math> , around the Larmor frequency <l:math xmlns:l="http://www.w3.org/1998/Math/MathML"> <l:msub> <l:mi>ν</l:mi> <l:mn>0</l:mn> </l:msub> </l:math> as a function of <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:msub> <m:mi>ν</m:mi> <m:mi>comb</m:mi> </m:msub> </m:math> . This offers an enhanced sensitivity to the quadrupolar split portion of the line. Using this method, we find a small decrease in the quadrupolar frequency with increasing temperature, showing the typical behavior associated with thermally excited phonons and the absence of any magnetic response, in contrast to what was observed for other defects in <n:math xmlns:n="http://www.w3.org/1998/Math/MathML"> <n:mrow> <n:mn>2</n:mn> <n:mi>H</n:mi> <n:mtext>−</n:mtext> <n:msub> <n:mi>MoTe</n:mi> <n:mn>2</n:mn> </n:msub> </n:mrow> </n:math> .