Blochsfäärän

Blochsfäärän is a concept in quantum mechanics that describes the state of a qubit. A qubit, unlike a classical bit which can only be 0 or 1, can exist in a superposition of both states simultaneously. The Bloch sphere is a geometrical representation of these possible states. It is a unit sphere, meaning its radius is one.

The north pole of the Bloch sphere typically represents the state |1⟩, and the south pole represents the state |0⟩. Any other point on the surface of the sphere represents a superposition state. These superposition states can be written as a linear combination of |0⟩ and |1⟩: α|0⟩ + β|1⟩, where α and β are complex numbers. The magnitudes of these complex numbers are related by |α|^2 + |β|^2 = 1, which ensures that the total probability of measuring either 0 or 1 is one.

The position of a point on the Bloch sphere is uniquely determined by two angles, similar to spherical coordinates. These angles define the specific superposition of the qubit. Rotations of a qubit's state correspond to rotations of the point on the Bloch sphere. This geometric visualization is a powerful tool for understanding and manipulating quantum states in quantum computing and quantum information processing.