Squeezed Coherent States

Squeezed coherent states are special quantum states that feature a reduced uncertainty in a certain physical quantity compared to the so-called standard quantum noise. This reduction in uncertainty occurs at the expense of increased uncertainty in another complementary physical quantity.

In quantum mechanics, uncertainty is described by Heisenberg's uncertainty principle. This states that there are physical quantities, such as position and momentum or time and energy, that cannot be determined simultaneously with arbitrary precision. The more precisely one quantity is measured, the greater the uncertainty in the conjugate quantity. Heisenberg's uncertainty principle is a fundamental property of quantum mechanics and contrasts with classical physics, in which no such uncertainty exists. Squeezed states are special states that can be created through targeted quantum mechanical manipulation and “squeeze” this uncertainty principle in a specific quantity. This means that in a squeezed state, the uncertainty in a selected quantity is reduced, while the uncertainty in the conjugate quantity is increased. This makes it possible to measure one quantity with greater precision, while the other quantity has lower precision. Such squeezed states play a role in various areas of quantum physics, quantum optics, and quantum information processing, especially in quantum sensor technology. Their targeted generation and manipulation is an important step toward the use of quantum mechanical effects for technological applications and in the exploration of fundamental quantum phenomena.

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