Two-dimensional Shubnikov–de Haas oscillations in PtSe 2 : A fermiological charge carrier investigation

High magnetic field and low temperature transport measurements are carried out in order to gain insight into the properties of the charge carriers of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:msub> <a:mtext>PtSe</a:mtext> <a:mn>2</a:mn> </a:msub> </a:math> . In particular, the Shubnikov–de Haas oscillations arising at applied magnetic field strengths <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:mrow> <b:mo>≳</b:mo> <b:mn>4.5</b:mn> <b:mspace width="0.28em"/> <b:mtext>T</b:mtext> </b:mrow> </b:math> are found to occur exclusively in plane. An analysis of the oscillations via the Lifshitz-Kosevich formalism allows determining the charge carrier's cyclotron mass, quantum transport time, Berry phase, Fermi surface cross section, and Dingle temperature. The oscillations emerge at a layer thickness of <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mrow> <d:mo>≈</d:mo> <d:mn>18</d:mn> <d:mspace width="0.28em"/> <d:mtext>nm</d:mtext> </d:mrow> </d:math> and decrease in frequency for thinner <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"> <f:msub> <f:mtext>PtSe</f:mtext> <f:mn>2</f:mn> </f:msub> </f:math> flakes. Further, weak antilocalization (WAL) is observed despite the presence of magnetic moments from Pt vacancies, which typically inhibit such effects. An explanation is provided on how WAL and the Kondo effect can be observed within the same material.