A quantum computer is a new kind of computer. Regular computers store memory in bits: 0s and 1s. Quantum computers store memory in qubits: ups, downs, sideways, and every direction in between (full guide here). This is a brand-new language for computing, and it turns out to be much more powerful for some tasks.
So what exactly can quantum computers do? We're finding new applications every month. The top three by impact today are:
- 1
Chemistry
The computational chemical factory
Design new molecules in minutes instead of millennia.
- 2
Security
The global decrypter
Every secure protocol on the internet is at risk.
- 3
Optimization
The live business optimizer
Solve the impossible scheduling problems.
The computational chemical factory
If we asked AI to invent a new space-age alloy that's lighter than air, stronger than steel, and hot pink, it might come back with a chemical formula in twenty seconds.
Whatever formula it spits out, verifying that it's actually true would take a regular computer about eight billion years.
8B
years
To verify a single mid-sized molecule's properties computationally. Longer than the age of the Earth.
Some problems are just brutally slow on regular computers. Material property verification is one of them. And it really sucks, because so much progress depends on it.
Why it's so hard
To determine the properties of a molecule, you need its electronic structure: how the electrons are distributed around the atoms.
Take an OLED molecule, the kind in your phone screen. To know what color of light it'll produce, you need the electron cloud:
The dense regions are where electrons are most likely to be found.
Why is this slow? Electrons fit together like puzzle pieces. They repel each other, so when one moves closer to a nucleus, another has to move farther away. Finding the most stable configuration means testing a staggering number of arrangements and checking which ones don't cram electrons too close to each other.
Physicists have been chipping away at this for decades. Several Nobel Prizes have been awarded for incremental speed-ups. Yet no algorithm can solve it for molecules with more than ~20 atoms when even one heavy element is involved (heavier elements like lead have more electrons, so the search space explodes).
What if we could?
If this weren't so slow, we could build a computational chemical factory: test billions of candidate molecules a day, and find the best ones.
🔋
Decade-long batteries
Materials that don't degrade after 1,000 charge cycles.
🛣️
Highways that never crack
Concrete formulations tuned for thermal expansion and freeze-thaw.
☀️
Sunscreen without the cancer risk
Organic UV filters with no oxidative byproducts.
This is the world I want to live in. Unfortunately, on classical computers, it can't happen. Those calculations genuinely take too long.
Quantum computers can test electron configurations exponentially faster than regular computers. They will enable the computational chemical factory. This is a trillion-dollar opportunity.
The global decrypter
The internet is secure because we encrypt the traffic between devices. Most of that encryption uses a protocol called ECDSA.
Every encryption algorithm depends on some assumptions. Most of ECDSA's assumptions are fine. Except one:
The assumption
Factoring a 256-bit number into two primes takes over 1 million years for any computer now or in the next 100 years.
It turns out quantum computers can factor those numbers easily. So quantum computers can decrypt internet traffic.
They can break more than that. When you download software, your computer checks that it was signed by a known developer like Microsoft, Adobe, or Apple. That signature check also relies on factoring being infeasible. Anyone with a sufficiently large quantum computer can sign software pretending to be Microsoft, and your machine will trust it. Same threat for code-signing, banking certificates, VPN keys, SSH access, and most of the cryptographic guarantees you don't think about every day.
This is a real and active world-security concern. Many companies are migrating to post-quantum cryptography: algorithms designed to resist quantum attacks. Some are moving fast. Most aren't moving fast enough.
The live business optimizer(potentially)
Businesses are extremely inefficient. The advanced ones use optimization algorithms to allocate resources better. Some examples:
- Investment firms use portfolio optimization to decide where to put money.
- Hardware companies turn their supply chains into optimization problems.
- Transportation companies solve routing and scheduling problems to keep customers happy (and, more often, save money).
Most of these optimizations take days, sometimes years. You can't do them live. In fact, most businesses don't even wait for them to finish. They cut them off after a set time and ship whatever the best answer was at that point. That leaves money on the table.
The honest caveat
Quantum computers might be able to do optimization significantly faster. But there are no guarantees. That's the problem with this field: it's almost impossible to prove an optimization method is better before you actually try it on hardware. Most researchers believe we have to wait for bigger quantum computers to see if this pans out.
What's next
Quantum computing still has a long way to go. But it brings with it the computational chemical factory, the global decrypter, and the live business optimizer.
Will you be the one to bring it to life?