{"id":"3019fea5-661a-4dc1-b325-307289a9c232","arxiv_id":"2605.13303","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":7.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"Direct magnetometry imaging establishes reconfigurable chiral superconductivity in rhombohedral graphene with low-current domain control.","lead":"Researchers used a nanoscale SQUID sensor to image magnetic domains in rhombohedral pentalayer graphene and detected time-reversal symmetry breaking that confirms chiral superconductivity. The domains can be switched reversibly with ultra-low currents, creating a reconfigurable superconducting state not seen in other materials.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"SQUID-detected magnetism may arise from the isospin-polarized normal state rather than TRS breaking inside the superconducting phase","rationale":"The reader's weakest assumption directly identifies the same ambiguity between normal-state isospin magnetism and superconducting TRS breaking. The abstract's mention of coincidence is suggestive but not decisive without the temperature-dependent local data; confirming the onset temperature would resolve the load-bearing uncertainty and could raise the verdict from UNVERDICTED.","tokens_in":1731,"tokens_out":322,"duration_ms":22419,"concrete_test":"Extract local SQUID flux maps at fixed density while sweeping temperature through the reported Tc; quantify the temperature at which domain contrast onsets and compare to transport Tc. If contrast appears only below Tc and tracks the superconducting dome, the TRS-breaking claim is supported; if it tracks the normal-state domain proliferation instead, the interpretation requires revision.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central claim of CSC rests on spatially resolved thermodynamic detection of TRS breaking via SQUID-on-tip imaging of domains whose proliferation coincides with the superconducting onset. However, the parent quarter-metal state is already isospin-polarized and can host orbital or valley magnetic moments; the manuscript does not appear to show explicit normal-state background subtraction or a sharp onset of the local magnetic contrast precisely at Tc (rather than at the density where domains appear at higher T). If the imaged fields persist above Tc or scale with the isospin polarization rather than the superfluid density, the attribution to chiral superconductivity weakens.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript uses nanoscale SQUID-on-tip magnetometry to image isospin-polarized domains in rhombohedral pentalayer graphene, claiming spatially resolved thermodynamic detection of time-reversal symmetry breaking that establishes chiral superconductivity (CSC). It reports that domain-wall proliferation at elevated temperatures coincides with CSC onset, that the chiral domain structure is inherited from the parent quarter-metal state, and that ultra-low currents enable deterministic, reversible switching between opposite-chirality states, with multiple transport regimes governed by domain configurations.","tokens_in":1843,"tokens_out":469,"duration_ms":23912,"significance":"If the central claims are substantiated, the work supplies the first direct magnetic imaging evidence for CSC in this platform and demonstrates reconfigurability via domain control, which is absent in other superconductors. This would strengthen proposals for topological superconductivity and open routes to low-power isospin-based electronics. The combination of imaging, transport, and switching data is a notable strength, provided the TRS-breaking signals are unambiguously tied to the superconducting phase.","major_comments":[{"comment":"SQUID magnetometry section (temperature-dependent imaging data): the manuscript does not show explicit normal-state background subtraction or demonstrate that the local magnetic contrast onsets sharply at Tc rather than at the density where domains appear above Tc. If the imaged fields persist above Tc or track isospin polarization instead of superfluid density, the attribution to TRS breaking inside the superconducting state is not secured.","section":"SQUID magnetometry results"},{"comment":"Transport and domain-wall resistance discussion: the claim that domain walls are the primary source of high resistance in the CSC phase requires quantitative comparison of resistance across different domain configurations with controls that isolate wall contributions from bulk or contact effects.","section":"Transport measurements"}],"minor_comments":[{"comment":"Figure captions should explicitly state the temperature and density ranges for each panel to allow direct comparison with the Tc line.","section":"Figure 3"},{"comment":"Notation for chirality states (e.g., + and -) should be defined consistently in the text and figures.","section":"Main text"}],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the careful and constructive review of our manuscript. We address each major comment below and have revised the manuscript to strengthen the presentation of the data where needed.","responses":[{"response":"We agree that explicit background subtraction and a clear demonstration of the temperature onset are essential to tie the magnetic contrast unambiguously to the superconducting phase. In the revised manuscript we have added panels showing the raw normal-state images, the subtracted data, and temperature-dependent line cuts. These establish that the local magnetic signal onsets sharply at Tc and is absent above Tc at the same densities, consistent with TRS breaking inside the superconducting state rather than the parent isospin-polarized quarter-metal phase.","revision_made":"yes","referee_comment":"[SQUID magnetometry results] SQUID magnetometry section (temperature-dependent imaging data): the manuscript does not show explicit normal-state background subtraction or demonstrate that the local magnetic contrast onsets sharply at Tc rather than at the density where domains appear above Tc. If the imaged fields persist above Tc or track isospin polarization instead of superfluid density, the attribution to TRS breaking inside the superconducting state is not secured."},{"response":"We acknowledge the need for quantitative controls. In the revised manuscript we have included additional transport data comparing the resistance of the same device in configurations with zero, one, and multiple domain walls (achieved via current-induced switching). These measurements, performed with identical contacts and at fixed density and temperature, show that the excess resistance scales with the number of domain walls while the bulk and contact contributions remain constant, thereby isolating the domain-wall contribution.","revision_made":"yes","referee_comment":"[Transport measurements] Transport and domain-wall resistance discussion: the claim that domain walls are the primary source of high resistance in the CSC phase requires quantitative comparison of resistance across different domain configurations with controls that isolate wall contributions from bulk or contact effects."}],"tokens_in":1373,"tokens_out":418,"duration_ms":30298,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The main point is that this paper images isospin-polarized domains with SQUID-on-tip and shows their proliferation lines up with the superconducting onset, plus they can flip the chirality with ultra-low currents. That reconfigurability is new for this system and gives a direct handle on the domains that transport data alone could not provide. They also tie the superconducting domain pattern back to the parent quarter-metal state, which helps explain the multiple transport regimes they observe. The experimental approach using nanoscale magnetometry is a solid addition here. The soft spot is the one the stress-test note flags. The parent state is already isospin-polarized, so orbital or valley moments could produce similar local fields. Without clear normal-state background subtraction or data showing the magnetic contrast turning on sharply at Tc instead of at higher temperatures where domains already exist, the attribution to chiral superconductivity stays plausible but not fully locked down. The abstract links domain walls to high resistance and CSC onset, yet the full temperature and density dependence would need to rule out carry-over from the normal state. This is for people working on graphene-based superconductors and topological states. A reader following rhombohedral multilayer systems or TRS-breaking superconductivity would get useful data from the imaging and switching results. The claims are specific enough and the methods direct enough that it deserves a serious referee rather than a desk reject, even if revisions will likely focus on the background controls.","headline":"SQUID imaging of switchable domains in rhombohedral graphene SC is a concrete step forward, but the signals need explicit checks to confirm they come from TRS breaking inside the superconducting phase rather than the polarized normal state.","tokens_in":2367,"tokens_out":370,"would_cite":false,"duration_ms":25749,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":{"model":"grok-4.3","evidence":[],"headline":"SQUID imaging of isospin domains and chiral SC in rhombohedral graphene shows no RS-shaped machinery","alignment":"orthogonal","rationale":"Paper centers on experimental magnetometry, transport hysteresis, domain-wall resistivity, and current-driven switching in a 2D graphene system. No J-cost, cosh(ρ ln φ), golden-ratio ladder, 8-tick periodicity, or parameter-free constant derivation appears; observations are interpreted via standard isospin polarization and TRS breaking, not RS forcing theorems.","tokens_in":65275,"confidence":"high","tokens_out":126,"duration_ms":16771,"cache_read_input_tokens":128,"cache_creation_input_tokens":0},"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"Rhombohedral pentalayer graphene shows chiral superconductivity with domains that switch chirality under ultra-low currents.","keywords":["chiral superconductivity","rhombohedral graphene","time-reversal symmetry breaking","domain walls","SQUID magnetometry","isospin domains","reconfigurable superconductivity"],"falsifier":"An experiment that finds the magnetic domains remain unchanged when current is applied across the superconducting transition or that low currents fail to reverse the chirality signal in magnetometry would falsify the reconfigurability claim.","tokens_in":2639,"feed_emoji":"🔄","tokens_out":505,"duration_ms":29565,"temperature":0.7,"pith_summary":"The paper establishes that superconductivity emerging from a spin-valley polarized quarter metal in rhombohedral pentalayer graphene breaks time-reversal symmetry and forms chiral domains. Nanoscale SQUID-on-tip magnetometry images these isospin-polarized domains directly and links their proliferation at elevated temperatures to the onset of chiral superconductivity. The domains inherit their structure from the parent state, and the chiral phase exhibits multiple transport regimes set by configurations of domains separated by resistive walls. Deterministic control with ultra-low currents allows reversible switching between states of opposite chirality, a feature the authors identify as absent in other superconductors.","feed_headline":"Ultra-low currents switch chirality in graphene superconductor","feed_subtitle":"Magnetometry images show domains inherited from a parent state that can be reversed reversibly, creating multiple transport regimes.","key_machinery":"Chiral domains and their highly resistive domain walls, inherited from the isospin-polarized parent state and manipulated by ultra-low currents to reverse chirality.","core_discovery":"We use nanoscale SQUID-on-tip magnetometry to image isospin-polarized domains in rhombohedral pentalayer graphene and establish chiral superconductivity via spatially resolved thermodynamic detection of time-reversal symmetry breaking. The density at which domain walls proliferate at elevated temperatures coincides with the onset of chiral superconductivity, indicating an underlying transition in the parent state that both induces superconductivity and reduces domain wall energy. The chiral domain structure in the superconducting phase is inherited from the isospin-polarized parent state. The CSC phase exhibits multiple transport regimes governed by configurations of chiral domains separated","pith_inferences":[],"forward_implications":[],"fun_headline_variants":["SQUID magnetometry images isospin domains in graphene","Chiral superconductivity imaged with nanoscale SQUID","Domain proliferation coincides with superconductivity onset","Reversible chirality switching via low current control","Multiple regimes from chiral domain configurations"],"cache_read_input_tokens":64,"weakest_assumption_plain":"The observed magnetic signals arise purely from time-reversal symmetry breaking in the superconducting state rather than from other magnetic or orbital effects, and domain walls are the primary source of the high resistance in transport.","fun_headline_variants_meta":{"raw":{"variants":["SQUID magnetometry images isospin domains in graphene","Chiral superconductivity imaged with nanoscale SQUID","Domain proliferation coincides with superconductivity onset","Reversible chirality switching via low current control","Multiple regimes from chiral domain configurations"]},"model":"grok-4.3","cost_usd":0.006355,"raw_usage":{"total_tokens":2924,"prompt_tokens":710,"num_sources_used":0,"completion_tokens":64,"cost_in_usd_ticks":63553000,"prompt_tokens_details":{"text_tokens":710,"audio_tokens":0,"image_tokens":0,"cached_tokens":64},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":2150,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":710,"tokens_out":64,"duration_ms":33606,"temperature":1.0,"reasoning_tokens":2150,"cache_read_input_tokens":64,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-05-14T18:36:37.732028+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"An experiment that finds the magnetic domains remain unchanged when current is applied across the superconducting transition or that low currents fail to reverse the chirality signal in magnetometry would falsify the reconfigurability claim.","supporting_citations":[],"review_version":1}