Physics · Year 12

Active learning ideas

Quantum Tunneling and Applications

Quantum tunneling’s abstract, probabilistic nature challenges students to move beyond classical physics intuition. Active learning through simulations, calculations, and design tasks lets students visualize wave functions, manipulate variables, and test predictions, which builds accurate conceptual models more effectively than passive delivery.

• ACARA Content Descriptions
• ACARA Australian Curriculum v9: Physics 11-12, Unit 4, explain the concept of wave-particle duality and how electron diffraction experiments provide evidence for this model (AC9P12U04)
• ACARA Australian Curriculum v9: Physics 11-12, Unit 4, use the formula λ = h/p to solve problems involving the de Broglie wavelength of matter (AC9P12U04)

• 20–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Tunneling Simulations

Set up three stations with PhET Quantum Tunneling simulator: one for varying barrier width, one for particle energy, and one for mass. Groups run trials, record probability data, and graph results. Rotate every 10 minutes and share findings in a whole-class debrief.

Explain how quantum tunneling allows particles to pass through energy barriers.

Facilitation Tip

During the Station Rotation, circulate to each group and ask students to predict what will happen to the wave function amplitude before they change barrier height.

What to look for

Present students with three scenarios: (A) an electron encountering a thin, low barrier, (B) an electron encountering a thick, high barrier, and (C) a proton encountering a moderate barrier. Ask them to rank the scenarios from highest to lowest probability of tunneling and justify their ranking using terms like barrier width, height, and particle mass.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Case Study Analysis
• 30 min · Pairs

Pairs: Probability Calculations

Provide worksheets with Schrödinger equation approximations for tunneling probability. Pairs select barrier parameters, compute values step-by-step using calculators, compare results, and predict outcomes for real devices like tunnel diodes.

Analyze the factors that influence the probability of quantum tunneling.

Facilitation Tip

For the Pairs Probability Calculations, provide calculators with exponent functions pre-programmed to reduce computational barriers and focus on conceptual reasoning.

What to look for

Facilitate a class discussion using the prompt: 'Imagine you are an engineer designing a new sensor. How could the principle of quantum tunneling be applied to detect extremely small changes in surface properties or molecular presence? What are the main challenges you would face?'

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 03

• Case Study Analysis
• 50 min · Small Groups

Small Groups: Device Design Challenge

Groups brainstorm and sketch a device using quantum tunneling, such as a flash memory cell. They outline required barrier specs, justify probability needs, and present prototypes to the class for feedback.

Design a device that utilizes quantum tunneling for a specific technological purpose.

Facilitation Tip

In the Small Groups Device Design Challenge, require teams to include a labeled diagram showing where tunneling occurs within their device before they present.

What to look for

On an index card, have students write a one-sentence definition of quantum tunneling in their own words and then list one technological application that would not be possible without this phenomenon.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 04

• Case Study Analysis
• 20 min · Whole Class

Whole Class: Analogy Demo

Demonstrate macroscopic analogy with microwaves passing through a metal grid. Class discusses similarities to electron tunneling, measures transmission vs. grid spacing, and links to quantum probabilities.

Explain how quantum tunneling allows particles to pass through energy barriers.

What to look for

Present students with three scenarios: (A) an electron encountering a thin, low barrier, (B) an electron encountering a thick, high barrier, and (C) a proton encountering a moderate barrier. Ask them to rank the scenarios from highest to lowest probability of tunneling and justify their ranking using terms like barrier width, height, and particle mass.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

A few notes on teaching this unit

Start with the Analogy Demo to ground abstract ideas in familiar contexts, then use simulations to let students manipulate variables and see immediate outcomes. Avoid over-relying on equations early; instead, build intuition with visuals and proportional reasoning before introducing mathematical formalism. Research shows that combining visualization with guided inquiry helps students reconcile probabilistic outcomes with deterministic expectations.

Students will confidently explain tunneling using wave functions, analyze how barrier parameters affect probability, and connect the concept to real-world applications. Success looks like students using precise terminology, justifying calculations with evidence from simulations, and proposing creative technological solutions during the design challenge.

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Watch Out for These Misconceptions

• During Station Rotation: Tunneling Simulations, watch for students attributing tunneling to particles gaining energy. Redirect them by asking, 'Look at the wave function graph inside the barrier. How does the amplitude change? What does that tell us about energy?'

  Have students measure the wave function amplitude at three points inside the barrier and relate it to the probability density. Ask them to explain why a non-zero amplitude on the far side means tunneling occurred without energy change.

• During Pairs: Probability Calculations, watch for students generalizing that tunneling happens at all scales. Redirect by asking, 'Try doubling the mass of your particle in the equation. What happens to the probability? Why might a cat not tunnel through a wall?'

  Guide students to scale mass by factors of 10 in the equation and observe the exponential drop in probability. Use the calculator’s output to discuss why macroscopic tunneling is imperceptible.

• During Small Groups: Device Design Challenge, watch for students assuming tunneling probability is fixed at 50 percent. Redirect by asking, 'Your device’s barrier is twice as wide as the example. How does this change your tunneling probability? What would you adjust to improve it?'

  Require teams to include a data table in their design showing how probability changes with barrier width, height, and particle mass. Use this to reinforce that probability is a precise outcome, not a random event.

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Methods used in this brief

• Stations Rotation
• Case Study Analysis