ECONOMIC DECOUPLING PROBABILITY: A Quantum Analogy of Characterizing Bell State Errors and Noise on Real IBM Quantum Hardware

Generating and measuring entangled states, specifically a two-qubit Bell state (superposition of 00 and 11), are crucial benchmarks for Noisy Intermediate-Scale Quantum (NISQ) hardware. This work benchmarks the fidelity of preparing this Bell state on different qubit pairs ([2, 3] and [7, 8]) on the ibm_kyiv processor over 5 runs. We employ the deviation from perfect correlation, measured by the probability of anti-correlated outcomes (01 or 10), as an analogy for unexpected decoupling in strongly correlated systems (e.g., economic indicators). Using a standard H+CNOT sequence (4096 measurements/run, SamplerV2 primitive), we characterized fidelity and applied mthree readout mitigation. Experimental raw results revealed significant variability, yielding mean anti-correlated probabilities of approx. 1.6% (std dev 0.3%) for layout [2, 3] and 9.2% (std dev 0.8%) for layout [7, 8]. This difference correlated strongly with calibration data, especially readout errors. Mitigation reduced anti-correlated probability to near-zero (at most 0.1%) for both layouts, achieving corrected correlated probabilities (00 or 11) of approx. 99.9-100.0%. The raw anti-correlated probability range provides an analogue for 'unexpected decoupling' likelihood under varying noise, while mitigation suggests isolating system dynamics from measurement noise. This work provides multi-run ibm_kyiv fidelity benchmarks, shows mitigation effectiveness, highlights variability linked to calibration, and quantifies the proposed economic analogy.