How does decoherence happen?

As a result of an interaction, the wave functions of the system and the measuring device become entangled with each other. Decoherence happens when different portions of the system’s wave function become entangled in different ways with the measuring device.

What is the state of superposition?

For an equation describing a physical phenomenon, the superposition principle states that a combination of solutions to a linear equation is also a solution of it. When this is true the equation is said to obey the superposition principle.

Why does superposition occur?

If waves from two sources spread out and cross throughout a region of space then superposition occurs at every point, and a pattern of interference is obtained. The superposition of waves from two sources can usually only result in an observable fixed (stationary) interference pattern if the sources are coherent.

How does a superposition work?

Introduction. The superposition principle is the idea that a system is in all possible states at the same time, until it is measured. After measurement it then falls to one of the basis states that form the superposition, thus destroying the original configuration.

What is decoherence in quantum mechanics?

The job of decoherence is to bring a quantum system into an apparently classical state. What especially differentiates a quantum system from a classical system is the concept of a superposition of states. In the classical realm of physics, we would say that a particle is at a position (x,y,z).

Does decoherence generate wave-function collapse?

Decoherence does not generate actual wave-function collapse. It only provides an explanation for apparent wave-function collapse, as the quantum nature of the system “leaks” into the environment. That is, components of the wave function are decoupled from a coherent system and acquire phases from their immediate surroundings.

Is decoherence a new theory unto itself?

Thus we clarify that decoherence is not a new theory unto itself, but is instead an efficient and fruitful repackaging of theory. It does not solve the measurement problem, and most certainly wouldn’t have satisfied the reservations of Einstein in his later years.

Does decoherence solve the measurement problem?

Decoherence has been developed into a complete framework, but there is controversy as to whether it solves the measurement problem, as the founders of decoherence theory admit in their seminal papers.