Deffner, Sebastian2025-03-112025-03-112025-01-29Deffner, Sebastian. "Towards Enhanced Precision in Thermometry with Nonlinear Qubits". Quantum Science and Technology 10, no. 2 (January 2025): 025009. https://doi.org/10.1088/2058-9565/adac05.http://doi.org/10.1088/2058-9565/adac05http://hdl.handle.net/11603/37782Quantum thermometry refers to the study of measuring ultra-low temperatures in quantum systems. The precision of such a quantum thermometer is limited by the degree to which temperature can be estimated by quantum measurements. More precisely, the maximal precision is given by the inverse of the quantum Fisher information. In the present analysis, we show that quantum thermometers that are described by nonlinear Schrödinger equations allow for a significantly enhanced precision, that means larger quantum Fisher information. This is demonstrated for a variety of pedagogical scenarios consisting of single and two-qubits systems. The enhancement in precision is indicated by non-vanishing quantum speed limits, which originate in the fact that the thermal, Gibbs state is typically not invariant under the nonlinear equations of motion.9 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.UMBC Quantum Thermodynamics GroupText