WEAK MEASUREMENT Meaning and
Definition
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Weak measurement refers to a type of measurement in quantum mechanics that provides information about a quantum system without significantly disturbing the system's state. It involves performing highly precise measurements with minimal interactions on the system being observed. Unlike traditional or strong measurements which drastically modify the quantum state of the system, weak measurements, also known as indirect measurements, aim to extract subtle information from the system while preserving its delicate quantum properties.
In weak measurement, the detection of a quantum system is performed via a small and gentle interaction with a measurement apparatus. This gentle interaction allows the system to maintain its superposition or coherence, enabling the measurement of certain properties that are not accessible through strong measurements. Weak measurement typically involves weakly coupling a measurement device to the system for a prolonged period before and after the measurement process. By analyzing the correlations between the pre- and post-selected states, weak measurements can extract information about the system's initial state and the effect of various operations on it.
Weak measurements have been employed in various experiments to study subtle aspects of quantum mechanics, such as the measurement of weak values and the investigation of quantum paradoxes. They have also found applications in fields like condensed matter physics, quantum computing, and quantum information processing. The concept of weak measurement provides a valuable tool for investigating quantum systems while minimizing the disturbance caused by measurements, paving the way for a deeper understanding of the fundamental laws of quantum mechanics.
Etymology of WEAK MEASUREMENT
The term weak measurement originates from the field of quantum mechanics. The word weak here refers to the fact that the measurement process in weak measurement is less intrusive or disruptive to the quantum system being observed, compared to strong measurements.
The etymology of the term itself is derived from the English language, where weak typically signifies the opposite of strong. In the context of quantum mechanics, weak measurement is a specific type of measurement technique that minimally disturbs the system being measured, thus the use of the term weak.
