12.2.4 Exploring quantum tunneling

• The width of the energy barrier must be small
• The wave function in quantum mechanics describes the probability of a particle's existence
• In the region before the energy barrier, the potential energy is zero
• What happens to a particle in classical mechanics if its energy is less than the barrier height?

  It is reflected
• What is quantum tunneling?

  Passing through energy barriers
• In classical mechanics, a particle can cross an energy barrier if its energy is less than the barrier height.

  False
• What factors does the tunneling probability depend on?

  Barrier height and width
• Order the regions based on their potential energy:

  1️⃣ Before Barrier (V = 0)

  2️⃣ Within Barrier (V > E)

  3️⃣ After Barrier (V = 0)
• What does the Schrödinger equation describe in the context of quantum tunneling?

  Wave function of particle
• What is the tunneling probability for an electron with 2 eV energy encountering a 5 eV barrier with a width of 1 nm?

  Non-zero
• The higher the energy barrier, the lower the tunneling probability.

  True
• Quantum tunneling is involved in alpha decay, allowing alpha particles to escape the nucleus.


  True
• Match the application of quantum tunneling with its description:

  Scanning Tunneling Microscope ↔️ Images individual atoms using tunneling current

  Tunnel Diodes ↔️ Enables fast switching in electronic circuits

  Alpha Decay ↔️ Alpha particles escape the nucleus

  Fusion in Stars ↔️ Light nuclei fuse together
• What is the condition for the height of the energy barrier in quantum tunneling?

  Substantial
• The Schrödinger equation describes the wave function of a particle.


  True
• Within the energy barrier, the Schrödinger equation describes exponential decay.


  True
• In quantum mechanics, particles pass through barriers via tunneling
• The tunneling probability depends on the height and width of the energy barrier.

  True
• Tunnel diodes exploit quantum tunneling for fast switching and amplification
• Order the steps involved in understanding quantum tunneling phenomena

  1️⃣ Solve the Schrödinger equation

  2️⃣ Calculate the tunneling probability

  3️⃣ Observe quantum tunneling in physical systems
• Quantum tunneling describes the wave function
• The Schrödinger equation describes the wave function
• How does a Scanning Tunneling Microscope (STM) use quantum tunneling?

  To image individual atoms
• What role does quantum tunneling play in stellar fusion reactions?

  Overcoming the Coulomb barrier