Physicists produce symmetry-protected Majorana edge modes on quantum computer
Scientists at Google Quantum AI used their quantum computers to study an effective particle type that is more resistant to environmental disturbances which can degrade quantum computations. Majorana edge mode effective particles are formed by a collective excitation multiple particles. Ocean waves, for example, result from collective motions in water molecules. Majorana edge mode applications are particularly interesting because they display special symmetries which can protect otherwise fragile quantum states against noise in the surrounding environment.
Since centuries, physics has focused on the relationship between physical phenomena and the underlying symmetries. Symmetries describe the transformations that a system is capable of undergoing, such as translation, rotation or inversion by a mirror, and still remain unchanged. They can clarify physical laws and simplify problems. As shown by the new research symmetries are able to prevent the quantum decoherence process that seems inexorable.
We want all the \”qubits\” in the quantum computer to be in one pure quantum state when we run a calculation. Decoherence is caused when external electric fields, or other environmental noises, disturb these states and mix them with other states in order to create unwanted states. It is possible to isolate a state that has a particular symmetry. This creates an island of stability, which cannot be mixed with other states. Since the noise cannot connect the symmetrical state with the others in this way, the state’s coherence can be preserved.