Incommensurate Antiferromagnetism in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>UTe</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> under Pressure

The discovery of multiple superconducting phases in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>UTe</a:mi></a:mrow><a:mrow><a:mn>2</a:mn></a:mrow></a:msub></a:mrow></a:math> boosted research on correlated-electron physics. This heavy-fermion paramagnet was rapidly identified as a reference compound to study the interplay between magnetism and unconventional superconductivity with multiple degrees of freedom. The proximity to a ferromagnetic quantum phase transition was initially proposed as a driving force to triplet-pairing superconductivity. However, we find here that long-range incommensurate antiferromagnetic order is established under pressure. The propagation vector <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi mathvariant="bold">k</c:mi><c:mi mathvariant="bold">m</c:mi></c:msub><c:mo>=</c:mo><c:mo stretchy="false">(</c:mo><c:mn>0.07</c:mn><c:mo>,</c:mo><c:mn>0.33</c:mn><c:mo>,</c:mo><c:mn>1</c:mn><c:mo stretchy="false">)</c:mo></c:math> of the antiferromagnetic phase is close to a wave vector where antiferromagnetic fluctuations have previously been observed at ambient pressure. These elements support that <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mrow><i:msub><i:mrow><i:mi>UTe</i:mi></i:mrow><i:mrow><i:mn>2</i:mn></i:mrow></i:msub></i:mrow></i:math> is a nearly antiferromagnet at ambient pressure. Our work appeals for theories modeling the evolution of the magnetic interactions and electronic properties, driving a correlated paramagnetic regime at ambient pressure to a long-range antiferromagnetic order under pressure. A deeper understanding of itinerant-<k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mi>f</k:mi></k:math>-electron magnetism in <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mrow><m:msub><m:mrow><m:mi>UTe</m:mi></m:mrow><m:mrow><m:mn>2</m:mn></m:mrow></m:msub></m:mrow></m:math> will be a key for describing its unconventional superconducting phases.