Antiferromagnetic Quantum Criticality in Infinite-Layer Cuprates Sr1-xNdxCuO2
The interplay between quantum criticality and Fermi surface reconstruction is central to elucidating the phase diagram of high-temperature cuprate superconductors. While studies on electron-doped T'-structure cuprates suggest an antiferromagnetic origin of this reconstruction, quantitative consensus has been hindered by apical oxygen instabilities and uncontrolled oxygen vacancies. Here, we overcome these limitations by utilizing ozone-assisted molecular beam epitaxy to synthesize high-quality, oxygen-stoichiometric thin films of infinite-layer cuprate Sr1-xNdxCuO2 across its entire superconducting dome. Hall transport measurements reveal a sharp carrier-type transition signaling a Fermi surface reconstruction at a critical doping xc ~ 0.155. We show that a spin-density-wave tight-binding model quantitatively reproduces the transport evolution, supporting an antiferromagnetic origin of this quantum phase transition. Furthermore, upon suppressing superconductivity with magnetic fields, the normal-state resistivity exhibits a pristine strange metal behavior that persists down to 2 K in the vicinity of xc. Our findings establish an intrinsic, universal antiferromagnetic quantum criticality in electron-doped cuprates, positioning the structurally simplest infinite-layer cuprates as a clean benchmark platform for theories of unconventional superconductivity.