Inducing Multitude of Terahertz Crystal‐Field and Spin Excitations Using Kramer Magnetism Relevant for Dissipationless Advanced Quantum Computing

ABSTRACT Wave‐based computations are envisioned as promising dissipationless alternatives to traditional electronic‐based systems that are limited by ohmic losses. The wave excitations can also incorporate the much‐desired ultrafast attribute of information processing, if the wave frequency lies in the terahertz (THz) region of the electromagnetic spectrum. Despite their considerable potential, systems hosting a relevant range of wave excitations remain relatively underexplored. Here, we invoke rare‐earth‐based non‐collinear magnets, wherein such opportunities can potentially be explored owing to the even/odd parity of f‐orbital electrons affecting the nature of crystal‐field excitations in accordance with Kramer's theorem, and their interactions with transition metal ions lead to the emergence of spin excitations, enriching the overall spectrum of excitations. Herein, we outline an approach to induce a wealth of intrinsic resonance excitations with enhanced quality factors in the low‐lying THz spectrum by exploiting Kramer's magnetism. Magneto‐THz spectroscopy of YbCrO 3 and its derivative systems reveals enhanced resonance features, significantly exceeding the reference systems. Based on the plethora of closely spaced intrinsic resonances, we present a method to control and modify the characteristics of these distinct excitations via rare‐earth magnetism, which can be exploited in THz hybrid quantum computing, as illustrated by our proof‐of‐concept proposition.