PHYS320 – A+ Quantum
Mechanics & Quantum Computing
Fundamentals
Core Principles, Key Concepts
& Practical Understanding
Latest Updated 2025–2026
What is quantum mechanics?
A physical science dealing with the behavior of matter and energy on the scale of atoms and
subatomic particles.
What significant contributions did Max Planck make to quantum mechanics?
He introduced the concept of quantized energy packets known as photons in 1900.
What is wave-particle duality?
The concept that electromagnetic radiation and matter exhibit both wave and particle properties.
What does the De-Broglie hypothesis propose?
That particles of matter, like electrons, can exhibit wave-like behavior, suggesting wave-particle
duality is a universal characteristic.
What is the Heisenberg Uncertainty Principle?
A principle stating that certain pairs of physical properties, like position and momentum, cannot both
be known to arbitrary precision.
What is a wave function?
, A mathematical description of the wave characteristics of a moving particle, represented as ψ(r, t).
What is the physical significance of the wave function?
It describes the probability of finding a particle at a given point in space and time.
What are Schrödinger's equations?
Mathematical equations that describe how the quantum state of a physical system changes over time.
What is the difference between time-independent and time-dependent Schrödinger equations?
The time-independent equation is used for systems with constant energy, while the time-dependent
equation accounts for changing energy states.
What is the tunneling effect?
A quantum phenomenon where particles pass through a potential barrier that they classically
shouldn't be able to cross.
What is the significance of the scanning tunneling microscope?
It uses the tunneling effect to image surfaces at the atomic level.
What is phase velocity?
The velocity at which a wave phase propagates through a medium.
What is group velocity?
The velocity at which the overall shape of a wave group travels through space.
What is the relationship between wavelength and momentum according to De-Broglie?
The wavelength (λ) is inversely proportional to the momentum (p) of a particle, given by λ = h/p.
What is the equation for kinetic energy in terms of momentum?
Kinetic energy (E) can be expressed as E = p²/(2m), where p is momentum and m is mass.
What does the probability density represent in quantum mechanics?
The likelihood of finding a particle in a specific location, calculated as |ψ(r, t)|².
What is the role of Planck's constant in quantum mechanics?
It acts as a bridge between the wave and particle aspects of quantum entities.
What is the significance of black body radiation in quantum mechanics?
It provided early evidence for the quantization of energy, leading to the development of quantum
theory.
What is the photoelectric effect?
The phenomenon where electrons are emitted from a material when it absorbs light, demonstrating
the particle nature of light.
What is the Compton effect?
The scattering of X-rays by electrons, which supports the particle theory of light.
What are the applications of quantum mechanics in engineering?
It plays a crucial role in fields like electrical engineering, materials science, and quantum computing.
What is the relationship between energy and frequency in quantum mechanics?
Energy (E) is directly proportional to frequency (ν) as described by the equation E = hν.
What is the concept of a particle in quantum mechanics?
Mechanics & Quantum Computing
Fundamentals
Core Principles, Key Concepts
& Practical Understanding
Latest Updated 2025–2026
What is quantum mechanics?
A physical science dealing with the behavior of matter and energy on the scale of atoms and
subatomic particles.
What significant contributions did Max Planck make to quantum mechanics?
He introduced the concept of quantized energy packets known as photons in 1900.
What is wave-particle duality?
The concept that electromagnetic radiation and matter exhibit both wave and particle properties.
What does the De-Broglie hypothesis propose?
That particles of matter, like electrons, can exhibit wave-like behavior, suggesting wave-particle
duality is a universal characteristic.
What is the Heisenberg Uncertainty Principle?
A principle stating that certain pairs of physical properties, like position and momentum, cannot both
be known to arbitrary precision.
What is a wave function?
, A mathematical description of the wave characteristics of a moving particle, represented as ψ(r, t).
What is the physical significance of the wave function?
It describes the probability of finding a particle at a given point in space and time.
What are Schrödinger's equations?
Mathematical equations that describe how the quantum state of a physical system changes over time.
What is the difference between time-independent and time-dependent Schrödinger equations?
The time-independent equation is used for systems with constant energy, while the time-dependent
equation accounts for changing energy states.
What is the tunneling effect?
A quantum phenomenon where particles pass through a potential barrier that they classically
shouldn't be able to cross.
What is the significance of the scanning tunneling microscope?
It uses the tunneling effect to image surfaces at the atomic level.
What is phase velocity?
The velocity at which a wave phase propagates through a medium.
What is group velocity?
The velocity at which the overall shape of a wave group travels through space.
What is the relationship between wavelength and momentum according to De-Broglie?
The wavelength (λ) is inversely proportional to the momentum (p) of a particle, given by λ = h/p.
What is the equation for kinetic energy in terms of momentum?
Kinetic energy (E) can be expressed as E = p²/(2m), where p is momentum and m is mass.
What does the probability density represent in quantum mechanics?
The likelihood of finding a particle in a specific location, calculated as |ψ(r, t)|².
What is the role of Planck's constant in quantum mechanics?
It acts as a bridge between the wave and particle aspects of quantum entities.
What is the significance of black body radiation in quantum mechanics?
It provided early evidence for the quantization of energy, leading to the development of quantum
theory.
What is the photoelectric effect?
The phenomenon where electrons are emitted from a material when it absorbs light, demonstrating
the particle nature of light.
What is the Compton effect?
The scattering of X-rays by electrons, which supports the particle theory of light.
What are the applications of quantum mechanics in engineering?
It plays a crucial role in fields like electrical engineering, materials science, and quantum computing.
What is the relationship between energy and frequency in quantum mechanics?
Energy (E) is directly proportional to frequency (ν) as described by the equation E = hν.
What is the concept of a particle in quantum mechanics?
