A Crash-Course on Quantum Computing

Written by TKS Las Vegas student Soleil Vivero (email:

Classical computers are extremely powerful tools that help us solve complex problems every day, but there are several areas where even they fall short.

Simulating the molecular structure of a compound? Nope. Calculating 500-digit numbers? Nah, it’ll crash. And God forbid you tell it to give you the best way to arrange your furniture, you’ll probably have to consult another human for that (ew).

Classical computers can’t do these things, but there’s a new type of supercomputer which can. They’re called quantum computers, and they open a gate to grandiose possibilities for scientific research, and with that, the human race.

IBM’s quantum computer: as graceful as a chandelier, but more powerful than a room of supercomputers. Its inverted pyramid structure allows it to choose outcomes with the least amount of energy through quantum annealing.

So What is a Quantum Computer?

What makes quantum computers so special is their use of subatomic particles and atoms as transistors (the yes/no switches for incoming info), which are called qubits (they have 0 & 1 values like normal computer bits). This allows the machine to operate using quantum mechanics, and with that, optimize its computational power. Most importantly, with a quantum principle called superposition.

  • Superposition: allows particles to be in multiple states at the same time — in this case, 0 and 1. If only I could be an electron and work and sleep at the same time…

Now let’s go back to qubits. We’ve already established that they can be in a 0 and 1 state at the same time, but how does that make quantum computers more powerful? Well, since each interacting qubit stays in a superposition until measured, their power eventually adds up to the square of the computational power of regular bits.

  • Computational power of qubits = 2^n the value of regular bits.

A diagram of what a qubit looks like. I’ll spare you the complicated math, all you need to know is that down = 1, up = 0, and the rest is the qubit in a superposition state.

So by now, you can start to see how quantum computers can get to be so powerful. They’re not just twice as powerful as a regular computer — they’re exponentially so. Granted, more power doesn’t necessarily mean more capacity, so it’s time to ask the question:

What Can We Do with This Power?

With this new processing speed and capability, scientists have begun using quantum computers for:

  • Optimization problems: these are problems that require one best solution out of several. Since qubits in superposition allow quantum computers to explore all possible solutions at the same time, they allow quantum computers to get to the best result MUCH faster than a regular computer, which would have to check each possibility one-by-one. This looks promising for supply chain logistics, which require a lot of optimization.
  • Cryptography: superposition can make the process of decrypting information a lot faster, but the possibilities go both ways. Another quantum principle called entanglement, which links two particles in perfect unison (think of them as mirrors from each other), could make it much harder for transaction eavesdroppers to get information since that would collapse the system and make all answers illegible.
  • Modeling new medicinal drugs and materials: scientists can now simulate molecules with more ease, which may bring new breakthroughs in medicine, chemistry, and creating new materials.

However, the best uses have probably not been thought of yet. I highly doubt the creator of the internet foresaw things such as online banking and “local hot babes in your area” becoming relevant, so these may just be the tip of the iceberg for the potential of quantum computers.

Cool! So…Where Can I Get One?

Sadly, quantum computers are not commercial yet — except for D-Waves, but they don’t have any significant advantages over classical computers, so I wouldn’t recommend getting one.

Ironically, superposition is what is preventing these computers from being more available. Particles in superposition are very fragile — things like fluctuations in temperature, sound, and even light can disrupt their quantum state and lead to errors in calculations.

But the future is not far. IBM claims they will make 50-qubit quantum computers commercially available in the next 4 years. 50 qubits will make it more powerful than a classical computer, but there is a lot of room for improvement. We may need to wait a decade or more to see the full power of quantum computers.

In the meantime, if you want to interact with a real quantum computer, you can on this website IBM made for developers who want to experiment with one. You could create a game of quantum Battleship while you wait for the real thing!

A sample of instructions for a game of Battleship in a quantum computer (our future is looking bright).

With the power of quantum computers, mapping complicated molecules and quickly computing highly complicated problems finally appear doable, and within a few short years, we will be able to help pave our way towards a brighter future with the help of these wonderful machines.