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University Quantum Mechanics I

University Quantum Mechanics I · Finite Square Wells · 7.07

The number of bound states, counted from z0

That one dimensionless depth parameter z0 fixes the count: a new state appears each time z0 passes a multiple of π/2, giving floor(2 z0/π) + 1 states in all, alternating even, odd, even.

Course-map guide · not a complete lesson or simulation

Scope & orientation

What this subsection covers

That one dimensionless depth parameter z0 fixes the count: a new state appears each time z0 passes a multiple of π/2, giving floor(2 z0/π) + 1 states in all, alternating even, odd, even.

A strong response uses tan and cot branches cut by the z0 circle and states where the model stops being reliable.

Reasoning checklist

Evidence, assumptions and limits

01

Assumptions to state

State the system, observable, approximation, and conditions held fixed before using a model.

02

Evidence to collect

Do graphical roots, a bracketed root-finder, and outward shooting return the same bound-state energies for one well, and where do they part?

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Do graphical roots, a bracketed root-finder, and outward shooting return the same bound-state energies for one well, and where do they part? Useful evidence includes the z0 circle plot with its intersections read off, roots from a bracketed solver, eigenvalues from shooting, the three sets tabulated against the floor(2 z0/π) + 1 prediction, and the tolerance at which the methods disagree..

03

Limits to state

This GioPhysics course map is an adaptable learning sequence, not academic credit, accreditation, or a universal university syllabus.

Read the complete note

This GioPhysics course map is an adaptable learning sequence, not academic credit, accreditation, or a universal university syllabus. It is a first dedicated quantum-mechanics course, distinct from University Physics V, which covers quantum mechanics alongside atomic, nuclear and particle physics in twenty units: this course is narrower, slower, and teaches the linear algebra it needs rather than assuming it. Hydrogen appears here as an introduction, with the full radial derivation belonging to a second course. A midterm examination is assumed around week 8. Follow your institution's published scope, notation, laboratory programme, and assessment rules. A result should be checked against units, signs, limiting cases, and the conditions under which its model was derived.

Diagram & examples

Work the claim before choosing an equation

Interactive concept map

Follow the model from claim to evidence.

01 · Physical claimThe number of bound states, counted from z0

That one dimensionless depth parameter z0 fixes the count: a new state appears each time z0 passes a multiple of π/2, giving floor(2 z0/π) + 1 states in all, alternating even, odd, even.

Read the complete note

That one dimensionless depth parameter z0 fixes the count: a new state appears each time z0 passes a multiple of π/2, giving floor(2 z0/π) + 1 states in all, alternating even, odd, even. There is always at least one, however shallow the well - a guarantee peculiar to one dimension, since a shallow three-dimensional well can bind nothing at all.

02 · RepresentationThe subsection's claim

Model, evidence, and boundary

03 · TestPrediction before measurement

What is the strongest test of a claim about The number of bound states, counted from z0?

04 · Evidence & boundaryDecide, then qualify

Do graphical roots, a bracketed root-finder, and outward shooting return the same bound-state energies for one well, and where do they part?

Read the complete note

Do graphical roots, a bracketed root-finder, and outward shooting return the same bound-state energies for one well, and where do they part? Useful evidence includes the z0 circle plot with its intersections read off, roots from a bracketed solver, eigenvalues from shooting, the three sets tabulated against the floor(2 z0/π) + 1 prediction, and the tolerance at which the methods disagree..

Interactive diagram for The number of bound states, counted from z0: follow the physical claim through its representation, proposed test, evidence, and model boundary.

modelModel, evidence, and boundary turns the stated idea into a representation that can make a prediction.

Example questions

Try the reasoning before revealing the structure.

Diagram check

What is the strongest test of a claim about The number of bound states, counted from z0?

Quick check

Test the reasoning, not recall

What is the strongest test of a claim about The number of bound states, counted from z0?

Choose an answer to test the model.