Quantum Computing: From Zero to Hero

What Is Quantum Computing and How to Harness It?

For starters, quantum computers use subatomic particles as the basic unit for doing computations. To be more exact, they use quantum bits; also known as qubits.

“Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical, and by golly, it’s a wonderful problem because it doesn’t look so easy.” — Richard Feynman

Two of the most important aspects of qubits are Entanglement and Superposition.

“One key factor in this development is how quantum mechanics allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart.” — Entangled states from theory to technology.

The more entangled bits, the more calculations quantum computers can do.

Superposition refers to the ability of a quantum system to be in multiple states at the same time until it is measured.

One of the biggest misconceptions concerning superposition is that it applies only to two states, but in reality, superposition refers to two or more states and is not always uniform meaning that the states can have different probabilities.

Naturally, the act of measurement will disturb the coherent superposition of states.

How Does It Work?

You might wonder how qubits are manipulated in quantum computers; the answer is microwaves. The quantum bits are actually quantum particles like electrons or photons which are operated at low temperatures using microwave pulses.

Naturally, quantum computers don’t work at room temperature; they need ultracold temperature (near zero Kelvin, or -273.15 Celsius)

Can I Use It?

The most popular SDK is Qiskit which provides the medium for end-users to interface with systems hardware and perform complex computing operations like simulation, optimization, and artificial intelligence.

At its core Qiskit is a quantum circuit construction, optimization, and execution engine, and by quantum circuit I mean a computational routine. Basically, you can mimic the execution of a quantum circuit, and the workflow will consist of four steps:

• Build the quantum circuit that models the problem you are considering.

• Compile the circuit for the desired quantum service: quantum system- the online quantum processors are the IBM Quantum systems or local classical simulators.

• Run the compiled circuits.

• Analyze the summary statistics and visualize the results of the experiments.

How It Will Evolve and How It Will Impact Society

Of course, some of the big players are tech giants ala IBM, Microsoft, Amazon, and Google are already involved.

IBM has a rich history of quantum computers; David P. DiVincenzo (former IBM) proposed the minimal requirements for creating a quantum computer, also known as the DiVincenzo criteria.

Nonetheless, there are some well-funded startups like Rigetti, IQM, and Quantinuumm that are researching this domain, and in its roadmap, IBM has projected that a 1000+ qubit quantum computer will be available in 2023.

Even though the computing power increases exponentially with the number of qubits, quantum computers have fairly high error rates, but the purpose of a quantum computer isn’t classical computing problems; rather, it is more suited for simulations or artificial intelligence tasks.

Just think about simulating a chemical reaction; it’s impossible even for the most powerful supercomputer to simulate molecular interaction, i.e., molecule modeling.

As a closing note, I would like to share the following quote which I feel encompasses the very essence of quantum computing.

“Using quantum principles to compute is as different from classical computing as a classical supercomputer is from an abacus” — William Phillips