The building block of Amazon's quantum computer design is an oscillatorВ that fluctuates in a coherent fashion-that is, the oscillationsВ moveВ in phase, or lockstep. Amazon's new blueprint relies on the choice to use so-called вЂњcat states,вЂќВ which consist of pairs of states as opposed to one another as the states of life and death experienced by the original SchrГ¶dingerвЂ™s cat. Scientists can theoretically encode a qubit using virtually any pair of states of a quantum system-for example, two of a molecule's potentially many different energy levels. Now the AWS Center for Quantum Computing has released a theoretical blueprint for a fault-tolerant quantum computer that intrinsically suppresses a major source of errors. However, such strategies often demand high overheads in terms of hardware - for example, they may require more than 1,000 redundant вЂњphysicalвЂќВ qubits for every useful вЂњlogicalвЂќВ qubit.ДЄnother strategy involves designing quantum computers that areВ inherently stable against error. Scientists can compensate for these high error rates using redundant qubits. вЂњIf you look at the error rate gap in terms of where the hardware is now and where it needs to be to handle large-scale problems with known societal and commercial benefit, there's about a nine orders of magnitude gap,вЂќВ says Oskar Painter, head of Amazon Web Services (AWS)'s quantum hardware program and an experimental physicist at the California Institute of Technology. In theory, a quantum computer with 300 qubits could perform more calculations in an instant than there are atoms in the visible universe.ДЄ critical drawback of current quantum computers is how their inner workings are prone to errors. If two qubits are quantum-mechanically linked, or entangled, they can help perform 2^2 or four calculations simultaneously three qubits, 2^3 or eight calculations and so on.

This essentially lets each qubit perform two calculations simultaneously. Now Amazon has unveiled a new theoretical blueprint for a quantum computerВ based on combining hardware versions of lots of SchrГ¶dingerвЂ™s cats.Д¬lassical computers switch transistors either on or off to symbolize data as ones or zeroes, while quantum computers use quantum bits-qubits-that, because of the surreal nature of quantum physics, can exist in a state of superposition where they are both 1 and 0 at the same time. SchrГ¶dingerвЂ™s cat is a thought experiment in which a quantum event suspends a cat in a box in a nebulous stateВ between life and death:В the cat only definitely becomes alive or dead when someone looks in the box.

Schrodinger cats