{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.displaced-squeezed-state","code":"thing-q661063","url":"https://ver.cy/models/thing/q661063/","name":"displaced squeezed state","alternateNames":["squeezed state of light"],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.STA"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A displaced squeezed state is a quantum state of a bosonic mode obtained by applying a phase-space displacement to a squeezed state, usually meaning the pure Gaussian state |α,ζ⟩ = D(α)S(ζ)|0⟩.","purpose":"Enable an agent to identify, characterize, verify, and manipulate a displaced squeezed quantum state while preserving its mode, phase, and operator conventions.","scope":{"in":["Displacement and squeezing parameters for a specified bosonic mode","Operator ordering, quadrature normalization, and phase-reference conventions","First moments, quadrature covariance, and evidence for squeezing","Distinction between ideal pure states and noisy experimental approximations","State transformations and suitability for a specified measurement task"],"out":["General classification of all Gaussian quantum states","Multimode entanglement and two-mode squeezed-state structure","Engineering specifications of squeezers, mixers, and detectors","Complete communication or metrology protocols","Non-Gaussian states produced by photon addition, subtraction, or nonlinear processing"],"boundaries":[]},"distinguishingFeatures":["Under the adopted ideal definition, the state admits D(alpha)S(zeta)|0>; record the operator definitions before comparing parameter values.","For nonzero squeezing, a principal quadrature variance is below the declared vacuum variance, distinguishing the state from a coherent state.","For nonzero displacement, its phase-space mean is nonzero, distinguishing it from squeezed vacuum in the same reference frame.","Purity separates the ideal family from displaced squeezed thermal states; record noisy realizations as approximations unless a broader definition is adopted.","D(alpha)S(zeta)|0> and S(zeta)D(beta)|0> require a parameter conversion for comparison; their names alone do not establish different state families."],"structure":{"bundles":[{"id":"state-definition","name":"State definition","description":"Establish the mathematical family and the conventions needed to recognize an instance.","layers":[{"id":"operator-representation","name":"Operator representation","description":"Record the vacuum, mode, and ordered operations defining the state.","findings":[{"id":"ordered-state-construction","name":"Ordered state construction","description":"Adopt |psi>=D(alpha)S(zeta)|0>, with D(alpha)=exp(alpha a†-alpha* a) and S(zeta)=exp((zeta* a²-zeta a†²)/2); explicitly translate alternative conventions.","questions":[{"text":"Which source and operator definitions establish the supplied state's representation?","id":"ordered-state-construction-q01","kind":"provenance"},{"text":"Were displacement and squeezing applied in the stated order, or must their parameters be converted?","id":"ordered-state-construction-q02","kind":"definition"}]}]},{"id":"family-boundaries","name":"Family boundaries","description":"Separate strict membership, limiting cases, and broader experimental usage.","findings":[{"id":"pure-family-and-extensions","name":"Pure family and extensions","description":"The pure single-mode Gaussian construction supplies the provisional core; mixed preparations require explicit qualification. Reference: [Gaussian Quantum Information](https://arxiv.org/html/1110.3234v1).","questions":[{"text":"Does the registry intend only displaced squeezed vacuum, or also displaced squeezed mixed states?","id":"pure-family-and-extensions-q01","kind":"boundary"},{"text":"Are alpha=0 and r=0 included as limiting members or linked exclusively to neighboring concepts?","id":"pure-family-and-extensions-q02","kind":"boundary"}]}]}]},{"id":"phase-space-characterization","name":"Phase-space characterization","description":"Describe the displacement and noise ellipse in a common coordinate system.","layers":[{"id":"mean-and-reference","name":"Mean and reference","description":"Locate the displacement in the selected mode and phase frame.","findings":[{"id":"resolved-displacement","name":"Resolved displacement","description":"Record both quadrature means, their uncertainties, and the reference defining the displacement phase.","questions":[{"text":"What are the measured quadrature means and their joint uncertainty for the selected mode?","id":"resolved-displacement-q01","kind":"measurement"},{"text":"Which phase reference and mode-selection procedure make those means reproducible?","id":"resolved-displacement-q02","kind":"provenance"}]}]},{"id":"noise-ellipse","name":"Noise ellipse","description":"Resolve squeezed and anti-squeezed directions independently of the mean.","findings":[{"id":"centered-quadrature-noise","name":"Centered quadrature noise","description":"Record covariance eigenvalues and axis orientation. Ideal displacement changes first moments while preserving covariance. Reference: [Gaussian Quantum Information](https://arxiv.org/html/1110.3234v1).","questions":[{"text":"What are the minimum and maximum centered quadrature variances relative to calibrated vacuum noise?","id":"centered-quadrature-noise-q01","kind":"measurement"},{"text":"What is the squeezed-axis angle relative to the displacement and readout phases?","id":"centered-quadrature-noise-q02","kind":"measurement"}]}]}]},{"id":"experimental-identification","name":"Experimental identification","description":"Connect the proposed state description to preparation and measurement evidence.","layers":[{"id":"preparation-evidence","name":"Preparation evidence","description":"Track the input state and operations producing the measured output mode.","findings":[{"id":"displacement-preservation-check","name":"Displacement preservation check","description":"Check whether the implemented displacement preserves squeezing over the operating range; a microwave experiment demonstrates this possibility, not a universal apparatus guarantee. Reference: [Displacement of propagating squeezed microwave states](https://arxiv.org/abs/1601.06697).","questions":[{"text":"What input-state evidence and calibrated operation sequence support the preparation claim?","id":"displacement-preservation-check-q01","kind":"provenance"},{"text":"Does measured centered noise change with displacement amplitude or phase?","id":"displacement-preservation-check-q02","kind":"measurement"}]}]},{"id":"state-reconstruction","name":"State reconstruction","description":"Assess squeezing, Gaussianity, and purity at a declared observation plane.","findings":[{"id":"qualified-state-estimate","name":"Qualified state estimate","description":"Record phase-resolved measurement evidence, detector corrections, and Gaussian-model checks before using moments as a complete state description.","questions":[{"text":"Do calibrated data support sub-vacuum variance with quantified uncertainty at the stated observation plane?","id":"qualified-state-estimate-q01","kind":"measurement"},{"text":"What evidence supports Gaussianity and purity, and which conclusions depend on assuming them?","id":"qualified-state-estimate-q02","kind":"boundary"},{"text":"Are reported variances directly observed or inferred after correcting detection loss and electronic noise?","id":"qualified-state-estimate-q03","kind":"provenance"}]}]}]},{"id":"transformations-and-use","name":"Transformations and use","description":"Determine how operations affect the state and whether it meets a concrete task requirement.","layers":[{"id":"controlled-transformations","name":"Controlled transformations","description":"Predict and verify changes from displacement, rotation, squeezing, and loss.","findings":[{"id":"operation-dependent-state-update","name":"Operation-dependent state update","description":"Use a characterized channel to update moments and classification; Gaussian channels act on means and covariance, while noise can destroy ideal purity. Reference: [Gaussian Quantum Information](https://arxiv.org/html/1110.3234v1).","questions":[{"text":"Which operation and calibrated channel parameters produce the requested displacement or squeezing-axis change?","id":"operation-dependent-state-update-q01","kind":"action"},{"text":"After the operation, is sub-vacuum noise retained and is the output still an ideal-family member or a mixed approximation?","id":"operation-dependent-state-update-q02","kind":"boundary"}]}]},{"id":"task-suitability","name":"Task suitability","description":"Evaluate the state against a specified signal, readout, and resource budget.","findings":[{"id":"readout-alignment-and-benefit","name":"Readout alignment and benefit","description":"Require a task-specific comparison that includes readout angle, displacement, squeezing, phase fluctuations, and resource accounting before claiming an advantage.","questions":[{"text":"Which observable carries the target signal, and how should its readout axis align with the noise ellipse?","id":"readout-alignment-and-benefit-q01","kind":"action"},{"text":"What measured performance improvement remains against the chosen reference state under equal resource and loss conditions?","id":"readout-alignment-and-benefit-q02","kind":"measurement"},{"text":"What phase drift or excess-noise threshold makes the state unsuitable for the intended task?","id":"readout-alignment-and-benefit-q03","kind":"boundary"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of displaced squeezed state this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of displaced squeezed state this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of displaced squeezed state this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of displaced squeezed state this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of displaced squeezed state this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of displaced squeezed state this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Explain displaced squeezed states using physics textbooks and peer-reviewed sources.","Compute and plot their properties in simulations for learners and researchers."],"mustNot":["Present speculative applications of squeezed light as proven technology.","Confuse a displaced squeezed state with a coherent or plain squeezed state in teaching or analysis.","Misreport experimental results or noise levels achieved in published work.","Attribute results to researchers without citing their publications."],"requiresHuman":["Endorsing claims about quantum sensing or security products built on squeezed states."]},"ethics":{"considerations":["Quantum technology attracts hype; honest description protects buyers and funders.","Credit for discoveries matters to the researchers who made them."],"affectedParties":["Students and researchers","Funders and buyers of quantum technology"]},"owners":{"steward":"Nobody owns the concept; it belongs to the scientific commons.","roles":[],"masterSystems":[]},"relations":[{"target":"Q456782","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.displaced-squeezed-state","Wikidata: Q661063 (https://www.wikidata.org/wiki/Q661063)"]},"properties":{"applicability":"not-applicable","items":["Bosonic mode: Specified annihilation operator a, with [a,a†]=1, and associated temporal, spatial, spectral, or oscillator mode","Quadrature convention: Adopt x=(a+a†)/sqrt(2), p=(a-a†)/(i sqrt(2)), [x,p]=i, and vacuum variance 1/2; record conversions","Displacement: Complex dimensionless alpha; for D(alpha)S(zeta)|0>, alpha=(<x>+i<p>)/sqrt(2)","Squeezing parameter: zeta=r exp(i theta), r>=0, theta in radians; record the sign convention in S","Quadrature covariance: Real symmetric 2x2 matrix V with V_ij=<{Delta R_i,Delta R_j}>/2 and R=(x,p)","Observed squeezing: Minimum quadrature variance and -10 log10(V_min/V_vac) dB, with uncertainty and calibration plane","State classification: Ideal pure family member; experimentally supported approximation; mixed Gaussian extension; unresolved","Phase reference: Reference oscillator or frame, displacement phase, squeezing-axis angle, and phase stability"]},"recognition":{"applicability":"not-applicable","items":[]},"capabilities":{"applicability":"required","items":["Translate state parameters between documented quadrature and operator-order conventions.","Predict phase-dependent quadrature means and variances under the adopted state model.","Assess whether measurement evidence supports nonzero displacement and sub-vacuum squeezing.","Choose a displacement or phase rotation to align the state with a specified measurement.","Propagate the state through a characterized Gaussian channel and reassess its classification.","Compare candidate states for a task using explicit noise, phase-stability, and resource requirements."]},"hazards":{"applicability":"required","items":["Confusing displacement and squeezing operator order can produce an incorrect state specification.","Inconsistent phase or quadrature conventions can invalidate comparisons between predicted and measured squeezing.","Optical loss and environmental noise can reduce squeezing and undermine expected sensing performance.","Ignoring increased uncertainty in the conjugate quadrature can lead an agent to overstate measurement precision."]},"interfaces":{"applicability":"not-applicable","items":[]},"context":{"applicability":"required","items":["Displaced squeezed states are studied in quantum optics and other systems described by bosonic modes.","They represent states combining a nonzero mean field with reduced uncertainty in a selected quadrature.","They support research in precision sensing and continuous-variable quantum information."]}},"sources":[{"title":"Wikidata item Q661063: displaced squeezed state","url":"https://www.wikidata.org/wiki/Q661063","note":"identity and sense of the item"},{"title":"Wikipedia: Squeezed coherent state","url":"https://en.wikipedia.org/wiki/Squeezed_coherent_state","note":"general description of the item"}],"openQuestions":["Which authoritative registry source establishes whether this entry means strictly D(alpha)S(zeta)|0> or includes displaced squeezed mixed states?","Does the registry distinguish 'squeezed coherent state' by operator ordering, treat it as an equivalent family name, or link it elsewhere?","Should zero-displacement and zero-squeezing limits remain members of this entry or only appear as relations to neighboring models?","Is single-mode scope sufficient for the registered concept, or is a documented multimode extension required?","What application-specific evidence thresholds should govern acceptance of experimental approximations, especially Gaussianity, purity, and corrected squeezing claims?"],"resources":{"spec":"/models/things/publications/thing-q661063/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q661063/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T09:14:19Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"not-applicable","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"not-applicable","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:32+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties.","interaction.interfaces":"No specific standard, law or official classification is identified as directly governing this mathematical quantum state.","interaction.recognition":"A displaced squeezed state has no directly visible identifying appearance and requires measurement-based characterization."},"score":1.0}}