For pure states represented by vectors in a Hilbert space, it means that only the overall phase changes with time, which has no physical relevance. Such states are energy eigenstates.deepalakshmi said:Summary:: What does constant fidelity mean?
I have a fidelity between the initial state and final state is 1 at t=0,1,2...etc. What does it mean physically? Does it mean that the quantum state is not evolved here. But In quantum dynamics every physical system evolves with time.
The evolution of quantum state refers to the changes that occur in a quantum system over time. It is a fundamental concept in quantum mechanics, which describes how the state of a system evolves according to the laws of quantum physics.
In classical mechanics, the state of a system is described by its position and momentum, which can be precisely measured. In contrast, in quantum mechanics, the state of a system is described by a wave function, which contains all the information about the system. The evolution of quantum state is described by the Schrödinger equation, which is probabilistic and allows for the existence of superposition and entanglement.
The evolution of quantum state is influenced by several factors, including the initial state of the system, the interactions between particles, and external forces acting on the system. These factors can cause the state of the system to change over time, leading to phenomena such as decoherence and quantum entanglement.
Yes, the evolution of quantum state can be observed and measured through experiments such as quantum tomography and quantum state tomography. These techniques allow scientists to reconstruct the quantum state of a system and track its evolution over time.
The understanding of the evolution of quantum state has led to the development of technologies such as quantum computing and quantum cryptography. These technologies utilize the principles of quantum mechanics and the evolution of quantum state to perform tasks that are not possible with classical computers, such as solving complex problems and ensuring secure communication.