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Mathematics & logicExamples and counterexamples

Learn what a claim covers, explain why it works, and recognise an allowed case that shows it needs changing.

Method
Mathematics & logicCounting and zero

Count each object once, explain the final count, and distinguish quantity, position and identifying labels. Make zero’s role explicit.

Definition
Mathematics & logicNumber lines and order

Use number-line positions to compare whole numbers. Read the scale, recognise equality, and distinguish numerical distance from drawing size.

Definition
Mathematics & logicAddition and subtraction

Combine separate counts, remove a part, and find differences or missing parts. Connect objects, equations and number-line moves, then use tens and ones to regroup without changing value.

Definition
Mathematics & logicMultiplication and division

Count equal groups, distinguish sharing from making groups, and check with multiplication. Split calculations into parts; interpret zero and remainders in context.

Definition
Mathematics & logicFractions

Choose a whole, count equal fractional units, and connect sharing with division. Place fractions on the number line, including values beyond one, and explain what their numerator and denominator mean.

Definition
Mathematics & logic · Physics · MeasurementRatios and rates

Distinguish part-to-part ratios, fractions of a whole and rates with units. Scale quantities together, compare unit rates, and explain when a relationship is proportional. Check zero cases, starting amounts and whether a result fits its context.

Definition
Mathematics & logic · Physics · MeasurementQuantities and units

Describe a quantity as a numerical value with a unit, and distinguish its physical kind from its dimension. Build length, area, volume and rate units, check meaningful combinations, and separate exact unit relations from measurement uncertainty.

Definition
Mathematics & logic · Physics · MeasurementUnit conversions

Convert quantities with exact unit ratios, track cancellation through compound units, and apply the correct powers to area and volume. Distinguish temperature readings from differences, check dimensions and context, and retain measurement uncertainty when reporting.

Method
Mathematics & logic · Physics · MeasurementEstimation and uncertainty

Distinguish exact model values, rounded approximations and estimates from measurements. Declare the rounding rule, preserve information through calculations and unit changes, and interpret resolution, precision, accuracy and the stated uncertainty type without turning a report’s digits into guaranteed bounds.

Definition
Mathematics & logicVariables and expressions

Use symbols to name numbers or quantities, describe their allowed values, and evaluate expressions by replacing every occurrence consistently. Preserve grouping, signs, fractions and units, and distinguish a calculated value from solving an equation or proving two rules equivalent.

Definition
Mathematics & logicEquality and equations

Read equality as a relationship, find the permitted values that make an equation true, and justify one-step solutions by reversible operations on both sides. Work exactly with negative numbers and fractions, recognize all-solution and no-solution cases, and check the original equation, units and context.

Definition
Mathematics & logic · PhysicsCoordinates and tables

Locate a point from an ordered pair, read named axes and their scales, and connect the same values in words, tables and plots. Keep signs, fractions and units exact, distinguish an axis point from a quadrant point, and separate selected observations from a stated rule and its domain before drawing connections.

Definition
Mathematics & logic · PhysicsSlope and straight lines

Read a straight line as a stated relationship, calculate its slope from consistent signed coordinate changes, and interpret its intersections with the axes. Keep horizontal, vertical and coincident-point cases distinct, attach units and domain conditions to context models, and use numerical scales rather than appearance alone to judge a line’s change.

Definition
Mathematics & logic · Physics · MeasurementReading graphs

Read a graph’s quantities, units, ticks and context before judging its visual impression. Calculate differences, reference-based percentages and interval rates from the represented values; distinguish legitimate zoom from distorted spacing; and keep samples, interpolation, missing information, uncertainty and causal explanations separate.

Method
Physics · MeasurementObservables and measurement

Choose the physical quantity you want to investigate, specify the point, event or location involved, and explain how a reading relates to that quantity.

Method
PhysicsSystems and boundaries

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Method
PhysicsModels and assumptions

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Method
PhysicsHypotheses, laws and theories

Identify what a scientific statement does, examine its evidence and conditions, and avoid treating its name as a score for certainty.

Method
Mathematics & logic · PhysicsApproximations

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Approximation
Mathematics & logic · PhysicsSymmetry and invariance

Specify a transformation, identify what stays unchanged, and distinguish symmetry of an object from invariance of a physical model.

Mathematical statement
PhysicsConservation laws

Use a defined system and a named quantity to track transfers, distinguish changing parts from conserved totals, and check the conditions of energy and momentum balances.

Model
PhysicsEmergence and levels of description

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Model
Mathematics & logic · PhysicsVectors

Describe displacement with fixed-axis components, combine compatible vectors, and use small exact examples to introduce span, independence, basis and real vector spaces.

Definition
Physics · Information · MeasurementScientific records

Build an inspectable physics record, test and revise a bounded cart model, preserve processing history, and plan findable data with appropriate sharing conditions.

Method
PhysicsPosition, velocity and acceleration

Describe a point's motion on a chosen straight axis, then connect signed changes, instantaneous rates and one exact set of position, velocity and acceleration graphs.

Definition
PhysicsNewton’s laws and forces

Choose one body, identify the forces acting on it, and use their vector sum to distinguish acceleration, balanced motion and mutual interactions.

Model
PhysicsWork, energy and power

Connect force and displacement to changes in motion, follow a spring’s stored energy, and distinguish an energy transfer from its rate.

Model
Physics · MeasurementSpeed of light in vacuum

c denotes the speed of light in vacuum. Its numerical value is fixed exactly in SI units.

Definition
Physics · MeasurementPlanck constant

h denotes the Planck constant. Its numerical value is fixed exactly in SI units.

Definition
ModelSource checked

Kitaev chain and Majorana boundary modes

Physics

Research context

postgraduate concept · conditional · As of 2026-10-10

An ideal spinless one-dimensional p-wave pairing chain has a gapped topological phase with boundary Majorana modes for nonzero pairing and |μ|<2|t| in the uniform nearest-neighbour model.

Key knowledge

An ideal spinless one-dimensional p-wave pairing chain has a gapped topological phase with boundary Majorana modes for nonzero pairing and |μ|<2|t| in the uniform nearest-neighbour model. This is a Hamiltonian result. Zero-bias or parity signals in a device need alternative-state, finite-size and decoherence tests before being identified as usable topological qubits.

Values and equations

|μ|<2|t| (Δ≠0, uniform ideal chain)

μ,t,Δ
Chemical potential, hopping and pairing energies J or eV consistently

Conditions and scope

  • Open chain, nonzero pairing, appropriate bulk gap and uniform model parameters; the displayed boundary changes at gap closing.
  • Real spinful proximity devices require a justified effective spinless regime. Local Andreev bound states can imitate limited signatures; a toy-model solution is not a material detection.
Sources · 3

References

Sources retain their recorded scope. A source link alone does not establish verification of every statement.

  1. Unpaired Majorana fermions in quantum wires (2000/2001)Alexei KitaevResearch paperarxiv.orgRead source
  2. Colloquium: Topological insulators (2010)M. Zahid Hasan and C. L. KaneResearch paperarxiv.orgRead source
  3. Distinguishing topological Majorana bound states from trivial Andreev bound states (2018)Chun-Xiao Liu, Jay D. Sau and S. Das Sarma / University of MarylandResearch paperarxiv.orgRead source

Evidence and review

Inspected §§1–2: spinless superconducting chain, boundary modes, gap and chemical-potential phase condition; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication. Inspected §§II.A–II.C and III: Berry connection, Chern integer, edge index, time reversal and measured surface signatures; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication. Inspected §§I–VI: specified nanowire Hamiltonian, simulated barrier/end-state/sharp-potential protocols, limited local zero-bias discrimination; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication.

2026-10-10 · Author source inspection of the displayed claim, model assumptions and equations; independent exact-content and branch-inventory review is a separate gate. Contemporary status is a dated snapshot, not a promise of ongoing monitoring.

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research-physics-kitaev-chain-model
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Postgraduate & research reference