Quantum Computing works through three different quantum mechanical properties -, Superposition, Entanglement and Interference.
Superposition – a combination of states occurs that we would generally describe independently. I.e. when you play two musical notes. You are hearing a superposition of the two musical notes (IBM 2020).
Entanglement – two objects exist together at the same time. Affecting one object will affect the other in the same way, i.e. two coins spinning at the same time are entangled when they stop spinning, both land on the same side (IBM 2020).
Quantum interference – quantum states undergo a type of interference due to a phenomenon known as a phase. Similar to wave interference, two waves in phase, their amplitudes add and when two waves are out of phase their amplitudes cancel (IBM 2020).
Quantum systems use different properties to complete computations. I.e. quantum computation is finding the best solution among many possible solutions to find the bond length of a molecule with the lowest energy state. A supercomputer would struggle to complete this in a reasonable time (IBM 2020).
IBM states a quantum computer is made up of seven physical components: Qubit signal amplifier, input microwave lines, superconducting coaxial lines, cryogenic isolators, quantum amplifier, cryoperm shield and a mixing chamber (IBM 2020).
A qubit signal amplifier is the first of two amplifying stages and is cooled to a temperature of 4 Kelvin or -269.15 degrees Celsius (IBM 2020).
Input microwave lines are where a decrease in temperature occurs at each stage of the refrigerator, which is done to ensure the protection of the qubits from any thermal noise during the sending and readout signal process (IBM 2020).
Superconducting coaxial lines are used to minimise energy loss. The coaxial lines direct signals between the first and second amplifying stages are made off superconductors (IBM 2020).
Cryogenic isolators allow for qubit signals to travel through each stage without any compromise to the qubit quality by preventing thermal noise (IBM 2020).
Quantum amplifiers are the second amplification stage and are housed within a magnetic shield which captures and amplify processor readout signals while continuing to reduce thermal noise (IBM 2020).
Cryoperm shield is where the quantum processor sits and is protected from electromagnetic radiation to preserve the qubit quality (IBM 2020).
The final step is the mixing chamber which is the lowest part of the refrigeration process and provides the necessary cooling ability to bring the processor and other components down to a 15mk or -273.135 degrees Celsius. (IBM 2020).