Simulating Mass-Dependent Decoherence in Quantum Computers: Baseline Signatures for Testing Gravity-Induced Collapse

Abstract

We present a quantum computing simulation study of mass-dependent decoherence models inspired by Penrose's gravity-induced collapse hypothesis. According to objective reduction (OR) theory, quantum superpositions become unstable when the gravitational self-energy difference between branches exceeds a certain threshold, leading to a collapse time $\tau \approx \hbar / E_G$. In this work, we implement a mass-dependent dephasing noise channel, $p(m) = 1 - e^{-k m^{\alpha}}$, within the Qiskit AerSimulator, where $m$ is a proxy for the effective mass of a superposition, mapped to circuit parameters such as the number of entangled qubits or branch size. We apply this model to three canonical quantum computing experiments: GHZ state parity measurements, branch-mass entanglement tests, and Grover's search to generate distinctive collapse signatures that differ qualitatively from constant-rate dephasing. The resulting patterns serve as a baseline reference: if future hardware experiments exhibit the same scaling trends under ideal isolation, this could indicate a contribution from mass-dependent collapse processes. Conversely, deviation toward constant-noise behaviour would suggest the absence of such gravitationally induced effects. Our results provide a reproducible protocol and reference for using quantum computers as potential testbeds for probing fundamental questions in quantum mechanics.