QUANTUM CHEAT SHEET
If you want to understand quantum mechanics, the science of the extremely small, you must firstly accept objects that tiny do not act like anything we encounter in our daily lives.
Objects can appear in two places at once, can teleport, and can even interact across distances with nothing in between. Light can behave like a particle and matter can behave like a wave.
• Quantum: For the purposes of quantum mechanics, it means a ‘packet‘. Energy, light and particles can only appear in discrete, or quantised, amounts; they cannot appear in continuous infinitesimally variable amounts. What we know as a ’photon‘ is a single quantum, or packet, of light.
• Superposition: Unlike classical ’bits‘ which can either be in a 0 or a 1 at any time, qubits are considered to be in all possible states concurrently.
This is one of the main properties underpinning the immense power of quantum computing and allowing qubits to handle so much more information than classical bits. It is not until we measure the state the qubit collapses into only one state.
• Entanglement & teleportation: The strange phenomena by which actions on one particle will immediately affect any particle entangled with it, even when separated by significant space. Einstein called it ‘spooky action at a distance’, which has now been physically proven.
• Tunnelling: Another strange phenomenon in which particles can, with a low probability, borrow energy from their surrounds and tunnel to the other side of an otherwise-insurmountable barrier.