We propose that quantum measurement is a boundary event: a physically identifiable, irreversible transition in which a reversible system/pointer correlation is forced across an operational irreversibility threshold into objective classical record stabilization. We formulate a three-stage taxonomy separating reversible premeasurement (Stage 1), irreversible record formation (Stage 2, the boundary event), and memory reset (Stage 3), and identify the stage at which a Landauer-scale heat bound applies. Under explicit operational conditions (C1–C6) in the uncontrolled-decoherence regime, the record-formation channel must dissipate at least kB T ln 2 of heat per bit of classical mutual information I(X;Y). We propose a circuit-QED differential microcalorimetry experiment with matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether an objective record is stabilized. The measurand is the differential deposited energy ΔQ ≡ QON − QOFF, which isolates record-formation dissipation from common-mode backgrounds. The primary deep-quantum demonstration targets the temporal coincidence of heat onset and reversibility loss via a reversal-delay sweep (Control 3), providing a distinctive boundary-event signature even when ΔQ >> kB T ln 2. Near-floor residual tests (r ≡ ΔQ − kB T ln 2 · I(X;Y)) require lower-energy pointer implementations or elevated operating temperatures and are presented as a concrete roadmap. The bound is falsified if r is negative at high statistical significance under verified conditions.
We propose that quantum measurement is a boundary event: a physically identifiable, irreversible transition in which a reversible system/pointer correlation is forced across an operational irreversibility threshold into objective classical record stabilization. We formulate a three-stage taxonomy separating reversible premeasurement (Stage 1), irreversible record formation (Stage 2, the boundary event), and memory reset (Stage 3), and identify the stage at which a Landauer-scale heat bound applies. Under explicit operational conditions (C1–C6) in the uncontrolled-decoherence regime, the record-formation channel must dissipate at least kB T ln 2 of heat per bit of classical mutual information I(X;Y). We propose a circuit-QED differential microcalorimetry experiment with matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether an objective record is stabilized. The measurand is the differential deposited energy ΔQ ≡ QON − QOFF, which isolates record-formation dissipation from common-mode backgrounds. The primary deep-quantum demonstration targets the temporal coincidence of heat onset and reversibility loss via a reversal-delay sweep (Control 3), providing a distinctive boundary-event signature even when ΔQ >> kB T ln 2. Near-floor residual tests (r ≡ ΔQ − kB T ln 2 · I(X;Y)) require lower-energy pointer implementations or elevated operating temperatures and are presented as a concrete roadmap. The bound is falsified if r is negative at high statistical significance under verified conditions.
We propose that quantum measurement can be analyzed as an operational irreversibility transition, or boundary event in the limited operational sense used here: the protocol stage at which a reversible system/pointer correlation is driven across a practical irreversibility threshold into an operationally stable record-bearing channel. We formulate a three-stage taxonomy separating reversible premeasurement (Stage 1), irreversible record stabilization (Stage 2), and memory reset (Stage 3), and identify the stage at which known information-thermodynamic bounds become experimentally testable. Under explicit operational conditions (C1 to C6) in the uncontrolled-decoherence regime, known information-thermodynamic second-law bookkeeping specializes to a conditional prediction: the record-formation channel must dissipate at least kBT ln 2 of heat per bit of classical mutual information I(X;Y).We propose a circuit-QED differential microcalorimetry experiment with matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether the irreversible Stage 2 channel is opened. The measurand is the differential deposited energy ΔQ ≡ QON − QOFF, which isolates the branch-differential dissipative load associated with opening the Stage 2 channel from common-mode backgrounds. In the deep-quantum regime this signal is expected to be dominated by pointer-energy thermalization rather than by an isolated Landauer floor. The primary deep-quantum demonstration targets the temporal coincidence of heat onset and reversibility loss via a reversal-delay sweep (Control 3), providing a timing diagnostic of irreversibility onset even when ΔQ ≫ kBT ln 2. This timing test is not, by itself, a device-independent proof of objective classicality. Near-floor residual tests (r ≡ ΔQ − kBT ln 2 · I(X;Y)) require lower-energy pointer implementations or elevated operating temperatures and are presented as a roadmap. The bound is falsified if r is negative at high statistical significance under verified conditions.
We propose that the transition from reversible quantum correlation to an objective classical record is a thermodynamically irreversible process with a quantifiable heat signature. We formulate a three-stage taxonomy separating reversible premeasurement, irreversible record formation, and memory reset, and derive a conditional record-formation heat bound: under explicit operational conditions (C1 to C6) in the uncontrolled-decoherence regime (no work extraction/coherence-recovery channel), the irreversible record-formation channel must dissipate at least kB T ln 2 of heat per bit of classical information created, quantified by the mutual information I(X;Y) between a prepared classical label X and the recorded outcome Y. Using an explicit system/pointer/bath model, we identify the precise stage at which this Landauer cost is paid: not during unitary premeasurement coupling, but during irreversible environmental coupling, when the pointer becomes entangled with N >> 1 environmental degrees of freedom and the record is stabilized. We design a circuit-QED differential microcalorimetry experiment using superconducting qubits and nanocalorimeters (TES or SNS nanobolometer class). The protocol employs matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether an objective record is stabilized. The measurand is the per-shot differential deposited energy ΔQ ≡ Q_ON - Q_OFF, which isolates the record-formation contribution. Four primary controls (ground-state baseline, measurement-strength scaling, reversal-delay timing sweep, and prior-variation) discriminate from systematic effects. Sensitivity analysis using demonstrated nanobolometer performance shows detection is feasible with N ~ 2 × 10^9 to 8 × 10^9 ON/OFF pairs at 10 mK for Landauer-scale residual tests at SNR ~ 10 (for σ_Q ≈ 0.32 to 0.6 zJ and ΔQ_target ≈ 9.57×10^-5 zJ). The bound is falsified if the observed residual ΔQ - kB T ln 2 · I(X;Y) falls statistically below zero.
We propose that the transition from reversible quantum correlation to an objective classical record is a thermodynamically irreversible process with a quantifiable heat signature. We formulate a three-stage taxonomy separating reversible premeasurement, irreversible record formation, and memory reset, and derive a conditional record-formation heat bound: under explicit operational conditions (C1 to C6) in the uncontrolled-decoherence regime (no work extraction/coherence-recovery channel), the irreversible record-formation channel must dissipate at least kB·T·ln(2) of heat per bit of classical information created, quantified by the mutual information I(X;Y) between a prepared classical label X and the recorded outcome Y. Using an explicit system/pointer/bath model, we identify the precise stage at which this Landauer cost is paid: not during unitary premeasurement coupling, but during irreversible environmental coupling, when the pointer becomes entangled with N ≫ 1 environmental degrees of freedom and the record is stabilized. We design a circuit-QED differential microcalorimetry experiment using superconducting qubits and nanocalorimeters (TES or SNS nanobolometer class). The protocol employs matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether an objective record is stabilized. The measurand is the per-shot differential deposited energy ΔQ ≡ QON − QOFF, which isolates the record-formation contribution. Four primary controls (ground-state baseline, measurement-strength scaling, reversal-delay timing sweep, and prior-variation) discriminate from systematic effects. Sensitivity analysis using demonstrated nanobolometer performance shows detection is feasible with N ~ 2×109 to 8×109 ON/OFF pairs at 10 mK for Landauer-scale residual tests at SNR ~ 10 (for σQ ≈ 0.32 to 0.6 zJ and ΔQtarget ≈ 9.57×10-5 zJ). The bound is falsified if the observed residual ΔQ − kB·T·ln(2)·I(X;Y) falls statistically below zero.
We propose that the transition from reversible quantum correlation to an objective classical record is a thermodynamically irreversible process with a quantifiable heat signature. We formulate a three-stage taxonomy separating reversible premeasurement, irreversible record formation, and memory reset, and derive a conditional record-formation heat bound: under explicit operational conditions (C1 to C6), the irreversible record-formation channel must dissipate at least k_B T ln 2 of heat per bit of classical information created, quantified by the mutual information I(X;Y) between a prepared classical label X and the recorded outcome Y. Using an explicit system/pointer/bath model, we identify the precise stage at which this Landauer cost is paid: not during unitary premeasurement coupling, but during irreversible environmental coupling, when the pointer becomes entangled with N >> 1 environmental degrees of freedom and the record is stabilized. We design a circuit-QED differential microcalorimetry experiment using superconducting qubits and nanocalorimeters (TES or SNS nanobolometer class). The protocol employs matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether an objective record is stabilized. The measurand is the per-shot differential deposited energy Delta Q = Q_ON - Q_OFF, which isolates the record-formation contribution. Four primary controls (constant-preparation null, measurement-strength scaling, reversal-delay timing sweep, and prior-variation) discriminate from systematic effects. Sensitivity analysis using demonstrated nanobolometer performance shows detection is feasible with N ~ 10^9 ON/OFF pairs at 10 mK. The bound is falsified if the observed slope of Delta Q versus I(X;Y) falls statistically below k_B T ln 2.
We propose that the transition from reversible quantum correlation to an objective classical record is a thermodynamically irreversible process with a quantifiable heat signature. We formulate a three-stage taxonomy separating reversible premeasurement, irreversible record formation, and memory reset, and derive a conditional record-formation heat bound: under explicit operational conditions (C1 to C6) in the uncontrolled-decoherence regime (no work extraction/coherence-recovery channel), the irreversible record-formation channel must dissipate at least kB T ln 2 of heat per bit of classical information created, quantified by the mutual information I(X;Y) between a prepared classical label X and the recorded outcome Y. Using an explicit system/pointer/bath model, we identify the precise stage at which this Landauer cost is paid: not during unitary premeasurement coupling, but during irreversible environmental coupling, when the pointer becomes entangled with N >> 1 environmental degrees of freedom and the record is stabilized. We design a circuit-QED differential microcalorimetry experiment using superconducting qubits and nanocalorimeters (TES or SNS nanobolometer class). The protocol employs matched ON/OFF branches that share identical premeasurement pulses and routing losses, differing only in whether an objective record is stabilized. The measurand is the per-shot differential deposited energy ΔQ ≡ Q_ON - Q_OFF, which isolates the record-formation contribution. Four primary controls (ground-state baseline, measurement-strength scaling, reversal-delay timing sweep, and prior-variation) discriminate from systematic effects. Sensitivity analysis using demonstrated nanobolometer performance shows detection is feasible with N ~ 2 × 10^9 to 8 × 10^9 ON/OFF pairs at 10 mK for Landauer-scale residual tests at SNR ~ 10 (for σ_Q ≈ 0.32 to 0.6 zJ and ΔQ_target ≈ 9.57×10^-5 zJ). The bound is falsified if the observed residual ΔQ - kB T ln 2 · I(X;Y) falls statistically below zero.
We propose that the transition from quantum correlation to objective classical record is a thermodynamically irreversible process, and derive a bound: the irreversible record-formation channel must dissipate at least k_B T ln 2 of heat per bit of classical information created. Using an explicit system–pointer–bath model, we identify the precise stage at which this Landauer cost is paid: not during unitary premeasurement coupling, but during irreversible amplification when the pointer becomes entangled with N >> 1 environmental degrees of freedom. We formulate a record-formation heat bound and propose a circuit-QED differential calorimetry experiment using superconducting qubits and nanocalorimeters (TES or SNS nanobolometer class). The protocol compares heat dissipation between record-forming measurements and matched controls, yielding a differential observable ΔQ that suppresses dominant readout-chain backgrounds. Three control experiments (constant-preparation null test, measurement-strength scaling, and reversal-delay timing sweep) provide discrimination from systematic effects. Sensitivity analysis using demonstrated nanobolometer performance shows detection is feasible with N ~ 10^9 repetitions at 10 mK, achieving SNR ≳ 10. The bound is falsified if the observed slope of ΔQ versus classical information I(X;Y) falls statistically below k_B T ln 2.