Detection of two-level fluctuators in a silicon quantum dot under relaxed noise sensitivity constraints

Abstract Statistical evaluation of two-level fluctuators (TLFs) in quantum dots is essential for improving the coherence of silicon spin qubits. However, conventional methods detect TLFs only under high-sensitivity conditions, which limits the accessible voltage range for characterization. Here we introduce a method that detects individual switching of TLFs in a silicon quantum dot even at low-sensitivity conditions. This method can extract the voltage dependence near the conditions activating the TLF switching, which provides insight into TLF switching mechanisms. Our approach facilitates routine statistical characterization of noise caused by TLFs in silicon spin qubits.