Slow magnetic quantum oscillations in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>c</mml:mi></mml:math>-axis magnetoresistance of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>UTe</mml:mi><mml:mn>

Details of the electronic band structure in unconventional superconductors are key to the understanding of their fundamental ground state. The potential spin-triplet superconductor <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>, with <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:msub><b:mi>T</b:mi><b:mi mathvariant="normal">c</b:mi></b:msub><b:mo>≈</b:mo><b:mn>2.1</b:mn><b:mspace width="0.16em"/><b:mi mathvariant="normal">K</b:mi></b:mrow></b:math>, has attracted attention recently. Its main Fermi surface consists of weakly corrugated, two-dimensional Fermi-surface cylinders that run along the crystallographic <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mi>c</f:mi></f:math> axis. In addition, there is evidence for the presence of an additional small three-dimensional band. This has been discussed controversially as it may be essential for the realization of superconductivity in <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:msub><g:mi>UTe</g:mi><g:mn>2</g:mn></g:msub></g:math>. Here, we investigate the angle-resolved magnetoresistance and Hall effect in bulk crystalline samples with current along the <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:mi>c</h:mi></h:math> axis in fields up to <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"><i:mrow><i:mn>60</i:mn><i:mspace width="0.16em"/><i:mi mathvariant="normal">T</i:mi></i:mrow></i:math>. We observe low-frequency magnetic quantum oscillations with light effective masses that are most pronounced for magnetic field applied along the <l:math xmlns:l="http://www.w3.org/1998/Math/MathML"><l:mi>a</l:mi></l:math> axis. Two distinct frequencies indicate two separate changes in the Fermi-surface topology, likely connected with Lifshitz transitions. We discuss the origin of these oscillations in terms of magnetic breakdown, quantum interference, and other potential mechanisms.