Source: Deep Learning on Medium
Quantum Supremacy: Beginning of the End
We have just set foot on the moon.
Or it feels like that. Achieving quantum supremacy means that mankind has just taken a huge leap into the future. Currently supercomputers are used to make intense calculations and largely in the realm of deep learning and data processing. Google has developed a quantum supercomputer that’s orders of magnitude faster than the fastest supercomputer in the world. For comparison Google’s quantum computer, Sycamore, with a 54-qubit processor was able to perform a target computation in 200 seconds that would take the fastest computer at least 10,000 years to reproduce. Sycamore was built with 54 loops of wire through which current can flow at two different energies (1 or 0). The chip is placed under almost absolute zero temperatures (the temperature at which molecules stop moving). This makes energy levels exhibit quantum behavior.
The way that quantum bits (qubits) work is that they are in a superposition of the states of 0 and 1 which means that the qubit is technically in both states and in neither state. However, when “you” look at a qubit you for collapse to either to 1 or 0 state. With just two qubits interacting with each other, you need an amplitude for every single possible configuration of the two qubits. So, you would need an amplitude for 00, 01, 10, and 11. Now with 54 qubits you would need 2⁵⁴ amplitudes to observe every configuration which results in about nine quadrillion amplitudes. Definitely check out Scott Aaronson’s explanation to get a better understanding.
The way that Google benchmarked Sycamore was by running a basic circuit with simple logic gates and checking the results with classical techniques. They started with 12 qubits and continued to scale up until it was impossible to simulate based on the Schrodinger-Feynman Algorithm. Sycamore was built with two-dimensional grid where each qubit is connected to four other qubits. This made it possible for the qubits to interact easily with each other. Additionally, they made a control knob to turn off interaction between qubits which greatly reduced the errors.
The immediate most useful applications of this quantum computer is simulating quantum physics and quantum chemistry, both of which have been impossible to simulate on current supercomputers. The achievement of quantum supremacy can be likened to the first computer over 100 years ago. This is just the beginning of another technological revolution. Quantum computing invites the possibility of solving many of the world’s current problems including world hunger, curing aids and other diseases, etc. Quantum Computers will be able to solve problems that we haven’t even begun solving yet. Terraforming Mars, exploring other galaxies, human like AI, etc. Quantum computing will propel humanity into the space age and allow humanity to evolve with extraordinary advancements in technology.
However, quantum computing has the ability to replace many jobs that can currently only be performed by humans. Not only will blue-collar jobs be replace but white collar jobs will be replaced. It’s only a matter of time till we develop a quantum computing based artificial intelligence that can learn how to write programs and conduct research to learn more than any human possibly could. What will we do when the majority of current jobs are gone and college is no longer enough for humans to out perform quantum artificial intelligence? All of these events may still seem far-fetched but with this breakthrough in quantum supremacy they may be closer than we think.
Are we ready?