This paper presents experimental evidence that α-RuCl₃, a ruthenium-based material, realizes the Kitaev physics, a prototypical topological quantum spin liquid (QSL) in two dimensions. The authors confirm the strong spin-orbit coupling and low-temperature magnetic order in α-RuCl₃, which matches the predicted phase near the QSL. They also show that stacking faults, inherent to the highly 2D nature of the material, can explain some puzzling results from previous studies. Measurements of the dynamical response functions, especially at energies and temperatures above the interlayer effects, are naturally accounted for by deconfined physics expected for QSLs. By comparing these results to recent calculations of the pure Kitaev model, the authors propose α-RuCl₃ as a prime candidate for experimental realization of fractionalized Kitaev physics. The findings highlight the potential of α-RuCl₃ as a platform for studying exotic physics associated with frustrated quantum magnets and the realization of topological states of matter with fractional excitations.This paper presents experimental evidence that α-RuCl₃, a ruthenium-based material, realizes the Kitaev physics, a prototypical topological quantum spin liquid (QSL) in two dimensions. The authors confirm the strong spin-orbit coupling and low-temperature magnetic order in α-RuCl₃, which matches the predicted phase near the QSL. They also show that stacking faults, inherent to the highly 2D nature of the material, can explain some puzzling results from previous studies. Measurements of the dynamical response functions, especially at energies and temperatures above the interlayer effects, are naturally accounted for by deconfined physics expected for QSLs. By comparing these results to recent calculations of the pure Kitaev model, the authors propose α-RuCl₃ as a prime candidate for experimental realization of fractionalized Kitaev physics. The findings highlight the potential of α-RuCl₃ as a platform for studying exotic physics associated with frustrated quantum magnets and the realization of topological states of matter with fractional excitations.