Understanding Decoherence: Simplifying a Complex Concept in Quantum Mechanics

[Loren Booda]

Please describe decoherence simply to someone with a mostly complete undergraduate understanding of quantum mechanics.

 

[Demystifier]

I recommend the following pedagogic reviews written at an elementary level:
http://lanl.arxiv.org/abs/quant-ph/9803052
http://lanl.arxiv.org/abs/quant-ph/9908008
http://lanl.arxiv.org/abs/quant-ph/0505070
http://xxx.lanl.gov/abs/quant-ph/0312059

 

[Entropia]

Decoherence is a phenomenon in quantum mechanics where the delicate and often mysterious behavior of particles at the microscopic level becomes more predictable and classical-like at the macroscopic level. In other words, it is the process by which the quantum properties of particles, such as their superposition and entanglement, become "lost" or "leaked" into the environment, leading to a more classical and observable reality. This can occur due to interactions with other particles or even just through the act of measuring or observing the system. Essentially, decoherence helps explain why we experience the world in a classical, predictable way, even though the underlying reality at the quantum level may be much more complex and uncertain.