We report the first experimental observation of analog Hawking radiation signatures on a 156-qubit superconducting quantum processor (IBM Heron R2). Using a spatially-varying XY spin chain with engineered coupling profile J(x) = J₀[1 - κ·tanh((x-x_h)/w)], we create an analog event horizon where excitation transport is kinematically forbidden. Our Multi-Horizon Interleaved Layout (MHIL) architecture enables up to four simultaneous "Hawking universes" with O(1) circuit depth scaling, achieving 156-qubit operation in only 44 transpiled layers. We demonstrate: (i) spatial localization of entanglement flux at the analog horizon with ratio F_h/F_far = 83.2× under optimized error mitigation (44.3× under standard reproducible conditions); (ii) temporal causality with monotonic signal development (R² > 0.99); (iii) the characteristic ⟨XX⟩ ≈ -⟨YY⟩ anti-correlation signature (r = 0.997) consistent with squeezed pair production; and (iv) effective temperature scaling β ∝ 1/κ consistent with the Hawking relation. Statistical validation via shuffle control demonstrates 91.6% signal degradation under random bit permutation (p < 0.001), providing strong evidence that the observed signal relies on multi-qubit spatial correlations consistent with XY dynamics. Multi-scale validation across 20-80 qubits confirms 100% peak position accuracy at the horizon. We emphasize that our results demonstrate kinematic analogs—spatial localization and pair-correlation signatures—not thermodynamic Hawking temperature. The bond correlator F(link) = ⟨XX⟩ + ⟨YY⟩ serves as a transport proxy; Bell-CHSH analysis yields S ≈ 0.4 < 2, confirming correlations without certified entanglement. All experimental data, including IBM Quantum job identifiers, are provided for independent verification. Key Results (Bullet Summary for Cover Letter) 156-qubit Hawking analog — Largest quantum simulation of analog Hawking radiation to date 83.2× flux localization ratio — Order of magnitude above detection threshold (10×) O(1) depth scaling — MHIL architecture enables 20→156 qubit scaling in constant depth 91.6% shuffle validation — Rigorous statistical control ruling out marginal artifacts Multi-scale reproducibility — Validated across Mini (20q), Medium (40q), Large (80q) configurations Full transparency — All IBM Quantum job IDs provided for external verification PACS / Subject Codes 03.67.Ac (Quantum algorithms, protocols, and simulations) 04.70.Dy (Quantum aspects of black holes, evaporation, thermodynamics) 75.10.Pq (Spin chain models)
We report the first experimental observation of analog Hawking radiation signatures on a 156-qubit superconducting quantum processor (IBM Heron R2). Using a spatially-varying XY spin chain with engineered coupling profile J(x) = J₀[1 - κ·tanh((x-x_h)/w)], we create an analog event horizon where excitation transport is kinematically forbidden. Our Multi-Horizon Interleaved Layout (MHIL) architecture enables up to four simultaneous "Hawking universes" with O(1) circuit depth scaling, achieving 156-qubit operation in only 44 transpiled layers. We demonstrate: (i) spatial localization of entanglement flux at the analog horizon with ratio F_h/F_far = 83.2× under optimized error mitigation (44.3× under standard reproducible conditions); (ii) temporal causality with monotonic signal development (R² > 0.99); (iii) the characteristic ⟨XX⟩ ≈ -⟨YY⟩ anti-correlation signature (r = 0.997) consistent with squeezed pair production; and (iv) effective temperature scaling β ∝ 1/κ consistent with the Hawking relation. Statistical validation via shuffle control demonstrates 91.6% signal degradation under random bit permutation (p < 0.001), providing strong evidence that the observed signal relies on multi-qubit spatial correlations consistent with XY dynamics. Multi-scale validation across 20-80 qubits confirms 100% peak position accuracy at the horizon. We emphasize that our results demonstrate kinematic analogs—spatial localization and pair-correlation signatures—not thermodynamic Hawking temperature. The bond correlator F(link) = ⟨XX⟩ + ⟨YY⟩ serves as a transport proxy; Bell-CHSH analysis yields S ≈ 0.4 < 2, confirming correlations without certified entanglement. All experimental data, including IBM Quantum job identifiers, are provided for independent verification. Key Results (Bullet Summary for Cover Letter) 156-qubit Hawking analog — Largest quantum simulation of analog Hawking radiation to date 83.2× flux localization ratio — Order of magnitude above detection threshold (10×) O(1) depth scaling — MHIL architecture enables 20→156 qubit scaling in constant depth 91.6% shuffle validation — Rigorous statistical control ruling out marginal artifacts Multi-scale reproducibility — Validated across Mini (20q), Medium (40q), Large (80q) configurations Full transparency — All IBM Quantum job IDs provided for external verification PACS / Subject Codes 03.67.Ac (Quantum algorithms, protocols, and simulations) 04.70.Dy (Quantum aspects of black holes, evaporation, thermodynamics) 75.10.Pq (Spin chain models)
Abstract Hawking radiation, predicted in 1974, establishes a fundamental bridge between quantum mechanics, general relativity, and thermodynamics. Direct observation remains impossible for astrophysical black holes (T_H ~ 10⁻⁸ K), motivating the development of analog systems. We report the first large-scale kinematic analog of Hawking radiation on a superconducting quantum processor, utilizing IBM Quantum Heron (ibm_fez, 156 qubits) with four spin chains deployed across calibration-verified low-noise regions. Our Multi-Horizon Interleaved Layout (MHIL) architecture enables up to four simultaneous 'Hawking universes' with O(1) circuit depth independent of system size, requiring zero SWAP gates through native heavy-hex topology exploitation. We demonstrate: (i) spatial localization of entanglement flux at the analog horizon with ratio F_h/F_far = 83.2× under optimized error mitigation (44.3× under standard reproducible conditions) (threshold: 1.8×); (ii) monotonic temporal dynamics with R² = 0.999; (iii) multi-chain reproducibility across three independent horizons; (iv) rigorous statistical validation showing 91.6% signal degradation under shuffle control (p < 0.001, Cohen's d = 4.7), supporting a physical origin of the observed correlations. IMPORTANT CLARIFICATION: This work demonstrates KINEMATIC (not thermodynamic) analog Hawking radiation. We observe spatial localization and pair correlation signatures consistent with the kinematic aspects of Hawking's prediction. We do NOT measure a thermal Planck spectrum, do NOT extract a Hawking temperature T_H, and do NOT achieve Bell-CHSH violation (S ≈ 0.4 < 2.0). These limitations are explicitly acknowledged. Extensions include the first non-integrable regime simulation (98 qubits, disorder strength W = 0.65) and preliminary exploratory evidence of analog wormhole cross-throat flux (48 qubits, 5/5 seeds validated, p = 0.031—this preliminary result requires confirmation with larger sample size). These results establish the viability of kinematic analog Hawking simulations on NISQ superconducting processors accessible via cloud, opening quantum gravity phenomenology to the broader research community without specialized infrastructure.
Abstract We investigate measurement-induced effects on trans-horizon correlations in dynamic quantum circuits executed on IBM's 156-qubit superconducting processor (ibm_fez, Heron r2 architecture). We engineer a 40-qubit spin chain with a spatially-varying XX + YY coupling profile that creates an analog horizon at position x h = 20, where coupling strength reaches a minimum. We define a correlation contrast metric C = ⟨σ x iσ x j⟩ horizon − ⟨σ x σ x ⟩ exterior and compare three conditions: (i) unitary Trotter evolution (baseline), (ii) mid-circuit measurement with reset on qubits near the horizon, and (iii) control measurement on distant qubits. Each circuit was executed with 16,384 shots. The near-horizon measurement produces a (56.5 ± 1.9)% reduction in correlation contrast (95% CI from n = 5000 bootstrap resamples), while the control preserves (87.8 ± 2.1)% of baseline. Two ablation experiments constrain interpretation: removing the reset operation yields only a (2.6 ± 1.2) percentage point change, indicating that projective measurement—not state reset—drives the effect. Crucially, moving the measured subset 4 links away from the horizon collapses the reduction to (6.5 ± 2.3)%, yielding an 8.2 ± 1.4 ratio that demonstrates strong spatial localization. We additionally performed a flat-spacetime control with uniform coupling J(x) = J max on ibm_torino (Heron r1, 133 qubits), obtaining a baseline contrast that collapses to a small residual near zero (C = − 0.015, 95% CI [− 0.029, − 0.002]), confirming that the spatial structure arises from the engineered coupling profile rather than generic measurement artifacts. These results establish that mid-circuit measurement near an engineered coupling minimum preferentially disrupts correlations across that boundary, a signature qualitatively consistent with information-theoretic models of horizon physics.
We investigate measurement-induced effects on trans-horizon correlations in dynamic quantum circuits executed on IBM's 156-qubit superconducting processor (ibm_fez, Heron r2 architecture). We engineer a 40-qubit spin chain with a spatially-varying XX + YY coupling profile that creates an analog horizon at position xh = 20, where coupling strength reaches a minimum. We define a correlation contrast metric C = ⟨σxiσxj⟩horizon − ⟨σxσx⟩exterior and compare three conditions: (i) unitary Trotter evolution (baseline), (ii) mid-circuit measurement with reset on qubits near the horizon, and (iii) control measurement on distant qubits. Each circuit was executed with 16,384 shots. The near-horizon measurement produces a (56.5 ± 1.9)% reduction in correlation contrast (95% CI from n = 5000 bootstrap resamples), while the control preserves (87.8 ± 2.1)% of baseline. Two ablation experiments constrain interpretation: removing the reset operation yields only a (2.6 ± 1.2) percentage point change, indicating that projective measurement—not state reset—drives the effect. Crucially, moving the measured subset 4 links away from the horizon collapses the reduction to (6.5 ± 2.3)%, yielding an 8.2 ± 1.4 ratio that demonstrates strong spatial localization. We additionally performed a flat-spacetime control with uniform coupling J(x) = Jmax on ibm_torino (Heron r1, 133 qubits), obtaining a baseline contrast that collapses to a small residual near zero (C = − 0.015, 95% CI [− 0.029, − 0.002]), confirming that the spatial structure arises from the engineered coupling profile rather than generic measurement artifacts. These results establish that mid-circuit measurement near an engineered coupling minimum preferentially disrupts correlations across that boundary, a signature qualitatively consistent with information-theoretic models of horizon physics.
We report a gate-based quantum circuit that implements a qubit-truncated analog of pair creation, inspired by Hawking radiation phenomenology, and demonstrate certified Bell nonlocality on IBM Quantum hardware (ibm_fez, Heron R2, 156 qubits). Using a two-mode squeezing (TMS) gate mapping |00⟩ to cos(θ/2)|00⟩ + sin(θ/2)|11⟩, we generate entangled pairs across a designated ‘horizon’ position in a 20-qubit chain.Main results: CHSH Bell parameter S = 2.290 ± 0.010 (29.8σ shot-noise; >22σ conservative with systematics), entanglement witness W = 2.838 ± 0.004, and Bell-state fidelity F(|Φ⁺⟩) = 96%. Bootstrap resampling (10,000 iterations) confirms robustness (100% of samples violate classical bounds).Important caveat: this is a protocol demonstration for gravity-inspired entanglement certification on NISQ hardware, not a faithful simulation of Hawking radiation (no thermal spectrum / vacuum structure).
We implement a chiral spin-chain black hole simulator on IBM superconducting quantum hardware and probe, within a common microscopic framework, both semiclassical horizon physics and interacting quantum scrambling. We first measure the dispersion relation across the exterior, horizon and over-tilted interior regimes, reproducing the predicted evolution of the effective light-cone structure. To probe Hawking thermality, we prepare a localised excitation inside the horizon and monitor its density response at an exterior site, observing the predicted inverse relation between the peak arrival time and the surface gravity, thereby establishing a calibrated dynamical estimator of the Hawking temperature. Beyond the semiclassical regime, we continuously tune the interactions and distinguish non-exponential operator spreading in the free-fermion limit from Lyapunov-like OTOC decay in the strongly interacting chiral regime. These measurements use observable-specific Floquet circuits derived from the same parent chiral model, including its mean-field and coordinate-equivalent XY descriptions, to reduce circuit depth while preserving the physics relevant to each probe. Our results provide a unified programmable platform for studying horizon geometry, Hawking thermality and interacting scrambling on quantum hardware.
Abstract Hawking radiation is one of the quantum features of a black hole that can be understood as a quantum tunneling across the event horizon of the black hole, but it is quite difficult to directly observe the Hawking radiation of an astrophysical black hole. Remarkable experiments of analogue black holes on various platforms have been performed. However, due to the experimental difficulty of accurately constructing curved spacetime and precisely measuring the thermal spectrum, Hawking radiation and its quantum nature, such as entanglement, have not been adequately investigated. Based on the recent architecture breakthrough of tunable couplers for superconducting processors, we experimentally realize an analogue black hole using our newly developed chip with a chain of 10 superconducting transmon qubits with interactions mediated by 9 transmon-type tunable couplers. By developing efficient techniques to engineer the couplings between qubits via tuning couplers, we achieve both flat and curved spacetime backgrounds. The quantum walks of quasi-particle in the curved spacetime reflect the gravitational effect near the black hole, resulting in the behavior of Hawking radiation. By virtue of the state tomography measurement of all 7 qubits outside the analogue event horizon, we show that Hawking radiation can be verified. In addition, an entangled pair is prepared inside the horizon and the dynamics of entanglement in the curved spacetime is directly measured. Our results would stimulate more interests to explore the related features of black holes using the programmable superconducting processor with tunable couplers.