• Question: How do Q-bits work

    Asked by Fred jem to samg on 16 Jun 2025.
    • Photo: Sam Godwood

      Sam Godwood answered on 16 Jun 2025:

      There are two ways to answer this—how qubits work in theory, or how people actually build them in a lab. I work more on the theory side, so here’s that version.
      In a normal computer, everything is built from bits—tiny switches that can be either 0 or 1, like off or on. A qubit is like a quantum version of a bit. It’s small and isolated enough that it follows the rules of quantum mechanics ( the science of how really small things behave).

      Because of those rules, we can get a qubit to do a lot of things a normal bit can’t. For example, a qubit can be in a state of 0, 1, or a mix of both at the same time—that’s called `superposition`. And when you have several qubits, they can also get `entangled`, meaning the state of one qubit is linked to the state of another, no matter how far apart they are.

      This lets quantum computers do certain calculations way faster than normal computers. For example, with just 100 qubits, a quantum computer could represent more information than you’d need trillions of classical bits for—basically, more than a normal computer the size of the earth could handle.

Comments

  • Photo: aureliabrzezowska

    aureliabrzezowska commented on :

    Wonderful question:
    As someone who has experience in cyber and has touched onto quantum through quantum encryption here’s my understanding:

    Qubits are the opposite of bits which can only contain one state at any time, true or false. Qubits instead can be both states at once alongside anything in between. Due to this, they’re usually faster at doing calculations and can solve more complex problems for us that are very difficult. For encryption, this means that they can solve nearly all current encryption methods and keys and provide a way for hackers to intercept and read data. This is where new methods of quantum cryptography comes in and how the world is preparing for a new framework and standard of encryption, one that even a quantum computer can’t solve until hundreds of years later.

    Quantum computing is the future, sort of how traditional computers were the future at some point too!