Imagine a future in which a computer reduces the time and effort required to develop new drugs or saves lives with more accurate weather forecasting. Quantum computers find answers to complex sets of problems that today’s classical (non-quantum) computers are really bad at. Classical computers operate by sequentially manipulating “strings of bits” that can either be a “0” or a “1.” Quantum computers operate using “qubits” which can be a “0,” “1” or both simultaneously. Quantum computers can solve problems faster because “qubits” exist in multiple states simultaneously, allowing algorithms to complete their analyses in fewer steps than classical computers.
In May, I was excited to see that IBM made quantum computing available to the public on the IBM Cloud platform. I was eager to increase my quantum computing knowledge, so I signed up for access. Since I really didn’t know anything about qubits, superposition, entanglement, gates, or quantum algorithms, I spent four hours completing the quantum computing tutorial available through the portal. Quantum computing is different than traditional computer science, so you have to be willing to “let go of what you know.” Quantum computing involves computation, so you should be prepared for a high-school math refresher as you take the tutorial.
The portal has a quantum computing simulator called the “composer” that I used throughout the tutorial to try out the quantum computing concepts I was learning. The simulator’s user interface (shown below) looks a bit like sheet music. Each line represents a qubit. Quantum computer algorithms are created by “dragging and dropping” various logic gates onto lines and connecting them together. Just like classical computers have their “and” and “or” Boolean logic gates, quantum computers have “pauli operators,” “superposition” and “c-not” logic gates.
After I finished writing my quantum computing program, I used the composer to simulate the program, visualize the results and debug a program logic mistake I’d made. Now, for the really exciting part: finally, with a working quantum program, I used the composer to run my program on the IBM “real” five-qubit quantum processor. The quantum simulator and processor produced identical results.
Just like other cloud services, quantum computing is pay-per-use. Initially, my account was loaded with six “units” or credits. One run of my program costs between three and five units. IBM replenished my account the day after I used up my units so I could continue to explore quantum computing.
Now it’s your turn to imagine what’s possible. Start exploring the quantum computer by requesting your free ID from IBM.