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PROG-AM
FR-AM-0007

Pressure-Quenched Superconductivity — Retention of High-Pressure States at Ambient Pressure

Pressure-quench protocols can stabilise pressure-induced or pressure-enhanced superconducting states at ambient pressure.

EscalatingVS-03·since 2026-08-25
Verification Matrix

Verification position derived from the record’s assessments; dates show when Faultline first recorded each stage.

VS-01
Assertion
—
VS-02
Published evidence
—
VS-03
Audit
Current from 2026-08-25 — present
VS-04
Replication
—
VS-05
Operation
—
Stage first recorded Current verification position Not yet recorded
State Warrant
Current stateEscalatingVS-03
Why this state?Admitted following bounded FCIF Admission Review on 2026-08-25. Claim scope is deliberately limited to retention of superconducting states after pressure removal. It does not assert room-temperature superconductivity, commercial usability, permanent ambient-condition stability, or a general law for all pressure-induced quantum states.
Assessment summaryThe claim is supported by a cumulative experimental trajectory rather than a single headline result. Pressure-quench retention has been reported across multiple superconducting materials, culminating in the 2026 Hg1223 result retaining an enhanced transition temperature up to 151 K after decompression. That progression is sufficient to move the claim beyond EMERGING: the phenomenon has recurred across material systems and has been subjected to peer-reviewed experimental characterisation. The pressure state is ESCALATING because the evidence base is expanding in strength and generality while the decisive uncertainties remain open. The principal unresolved issue is independent replication outside the originating research network (RM-002). A second limitation is physical durability: ambient pressure is not equivalent to ambient-condition stability, because the retained Hg1223 state is metastable and degrades on warming (RM-001). Verification Stage is VS-03 — Audit: the published evidence has substantial internal controls and cross-material recurrence, but no unaffiliated laboratory has yet reproduced the pressure-quench effect under a shared protocol. Independent replication (AT-001) is therefore the next evidential boundary.
In this state since2026-08-25
Mechanisms

Causal mechanisms recorded for this claim. The State Warrant above remains the authoritative current assessment.

Resistance MechanismRM-001

Thermal metastability. Pressure quenching can remove the external pressure requirement while leaving the retained superconducting phase dependent on thermal history. In Hg1223, the enhanced state degrades when warmed and can lose much of its transition-temperature enhancement after excursions above roughly 200 K. This is a structural limitation: ambient pressure alone does not establish that the quenched phase can be stored, handled, or cycled under ordinary ambient-temperature conditions.

Resistance MechanismRM-002

Originating-group concentration. The cross-material evidence is stronger than a one-off observation, but the principal demonstrations are concentrated within one research programme and its collaborators. Until an unaffiliated laboratory reproduces pressure-quench retention using a published protocol, programme-specific technique, apparatus, sample preparation, or interpretation remain viable alternative explanations for the apparent generality.

Resistance MechanismRM-003

Protocol and history dependence. The retained state depends on pressure magnitude, quench temperature, decompression path, defects, stoichiometry, and potentially oxygen or vacancy rearrangement. Strong path dependence can make a phenomenon physically real while still preventing reproducible transfer between laboratories or material batches. The claim therefore requires protocol-level reproducibility, not merely repeated positive samples within one experimental lineage.

Resistance MechanismRM-004

Scale and recovery gap. Current demonstrations rely on very small samples processed under diamond-anvil-cell or comparable extreme-pressure conditions. Retaining a superconducting state after decompression does not yet show that useful quantities of material can be produced, recovered, processed, or incorporated into devices without erasing the metastable phase.

AttractorAT-001

Independent pressure-quench replication. An unaffiliated laboratory reproduces retention of a pressure-induced or pressure-enhanced superconducting state at ambient pressure using a published pressure-quench protocol and independent material preparation. This would remove the largest current verification bottleneck and justify movement beyond VS-03.

AttractorAT-002

Thermally durable retained high-Tc state. A pressure-enhanced superconducting state remains stable at ambient pressure through room-temperature handling and subsequent cooling cycles while preserving materially enhanced superconducting properties. This would distinguish pressure removal from genuinely usable ambient-condition retention and would materially change the technological significance of the claim.

Assessment History
2026-08-25
Initial assessment — Escalating
The claim is supported by a cumulative experimental trajectory rather than a single headline result. Pressure-quench retention has been reported across multiple superconducting materials, culminating in the 2026 Hg1223 result retaining an enhanced transition temperature up to 151 K after decompression. That progression is sufficient to move the claim beyond EMERGING: the phenomenon has recurred across material systems and has been subjected to peer-reviewed experimental characterisation. The pressure state is ESCALATING because the evidence base is expanding in strength and generality while the decisive uncertainties remain open. The principal unresolved issue is independent replication outside the originating research network (RM-002). A second limitation is physical durability: ambient pressure is not equivalent to ambient-condition stability, because the retained Hg1223 state is metastable and degrades on warming (RM-001). Verification Stage is VS-03 — Audit: the published evidence has substantial internal controls and cross-material recurrence, but no unaffiliated laboratory has yet reproduced the pressure-quench effect under a shared protocol. Independent replication (AT-001) is therefore the next evidential boundary.
Admitted following bounded FCIF Admission Review on 2026-08-25. Claim scope is deliberately limited to retention of superconducting states after pressure removal. It does not assert room-temperature superconductivity, commercial usability, permanent ambient-condition stability, or a general law for all pressure-induced quantum states.
Claim Lineage

Historical narrative recorded for this claim. It does not override the current State Warrant.

2020–22
Pressure quenching emerges as an experimental method for retaining superconducting states after decompression. Early Sb and FeSe demonstrations establish the proposition but remain narrow in material range and institutional origin.
2022–24
No unaffiliated replication is established in the record. The early Sb, FeSe, and Cu-doped FeSe reports remain concentrated within the originating research programme; their material range is informative but not independent confirmation.
2025
Bi0.5Sb1.5Te3 demonstrates retention of a pressure-induced superconducting phase at ambient pressure with recovery from the pressure apparatus. The method's scope expands beyond the originating material classes.
2026
Hg1223 pressure quenching retains an enhanced superconducting transition up to 151 K at ambient pressure, setting a new ambient-pressure record and making thermal durability and independent replication the decisive next questions.
Open Questions

Questions retained in this record. The current State Warrant may have narrowed or reframed earlier questions.

OQ-001

Is pressure quenching a broadly general method for trapping metastable superconducting states, or does successful retention depend on a narrow subset of materials with favourable structural or electronic transitions?

Raised 2026-08-25
OQ-002

What physically stabilises the retained state after decompression — defects, strain, oxygen or vacancy rearrangement, electronic reconstruction, or a combination of mechanisms — and can that mechanism predict which materials should be quenchable?

Raised 2026-08-25
OQ-003

Can a pressure-quenched high-Tc state survive room-temperature storage and handling and then recover the same enhanced superconducting properties on subsequent cooling?

Raised 2026-08-25
OQ-004

Can pressure-quench retention be reproduced by an unaffiliated laboratory from a published protocol without tacit knowledge from the originating research programme?

Raised 2026-08-25
Mutation Log
MutationDateFieldPrior valueCurrent value
M-0072026-09-22provenance_correctionLPR-001-D24 discrepancies_found / pendingLPR-001-D24 discrepancies_corrected / completed
M-0062026-09-22provenance_review—LPR-001-D24 REVIEW REQUIRED
M-0052026-08-25assessment_issued—AS-001
M-0042026-08-25opened_date_added—2026-08-25
M-0032026-08-25related_records_correctedbare record identifiersgoverned related-record objects
M-0022026-08-25instances_logged—IN-001–IN-004
M-0012026-08-25record_created—RECORD-CREATED
Evidence Sources
4 instances on recordShow sources ↓Hide ↑
IN-001Early pressure-quench demonstrations — superconducting states retained after decompression1. Wu et al., The retention at ambient of the high-pressure-induced metastable superconducting phases in antimony single crystals, Materials Today Physics 15, 100291 (2020) DOI 10.1016/j.mtphys.2020.100291 · Abstract — pressure-quenched metastable superconducting phases retained at ambient pressure2. Deng et al., Pressure-induced high-temperature superconductivity retained without pressure in FeSe single crystals, PNAS 118, e2108938118 (2021) DOI 10.1073/pnas.2108938118 · Abstract — FeSe and Cu-doped FeSe retained at ambient pressure by pressure quenchingsupportive
IN-002FeSe and Cu-doped FeSe — same-study composition comparison1. Deng et al., Pressure-induced high-temperature superconductivity retained without pressure in FeSe single crystals, PNAS 118, e2108938118 (2021) DOI 10.1073/pnas.2108938118 · Abstract and Figures 4–5 — pure and Cu-doped FeSe retained at ambient pressure after pressure quenchingsupportive
IN-003Bi0.5Sb1.5Te3 — pressure-induced superconducting phase retained and recovered at ambient pressure1. Deng et al., Creation, stabilization, and investigation at ambient pressure of pressure-induced superconductivity in Bi0.5Sb1.5Te3, PNAS 122, e2423102122 (2025) DOI 10.1073/pnas.2423102122 · Abstract — retained superconducting phase and recovery from diamond-anvil cell at ambient pressuresupportive
IN-004Hg1223 — ambient-pressure superconducting transition retained up to 151 K after pressure quench1. Deng et al., Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench, PNAS 123, e2536178123 (2026) DOI 10.1073/pnas.2536178123 · Abstract and experimental figures — ambient-pressure Tc up to 151 K after pressure quenchsupportive