coherence time


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coherence time

[kō′hir·əns ‚tīm]
(physics)
The average time required for the relative phase of two waves, or the phase of a single wave, to fluctuate appreciably.
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These ground-breaking innovations will increase the coherence time of the sample, Enable a higher detection efficiency, And exploit coherent effects, Thereby increasing the sensitivity tremendously.
In a demonstration of a part of a quantum memory device, scientists at Tsinghua University in Beijing made a qubit consisting of a magnetically trapped, positively charged ytterbium-171 ion, which achieved a coherence time of more than 10 minutes.
Say you're in a pub and you're trying to bring two pints of beer back to your friends, but the pub is filled with customers who are singing, jumping around, and dancing - the coherence time is a measure of how far you can get the beer without spilling it," Winpenny said in the statement.
The coherence time of his qubits, or the length of time they can maintain a superposition, is tens of microseconds--about 10,000 times the figure for those on D-Wave's chip.
However, because of the short coherence time, the non-orthgonal pilot is used in reality [18-20], Therefore, channel estimation of the massive MIMO system is not perfect.
where t is the coherence time and A is the Planck length.
Researchers estimated the lifetime and coherence time to be on the order of several microseconds, and found that sensitivity of the avian compass is enhanced by environmental noise, with long coherence times not required for navigation.
They were also able to achieve a fourfold prolonged coherence time of the light emission.
The intervals between transmissions of the same symbol should be at least the coherence time so that different copies of the same symbol undergo independent fading.
Active optical clocks provide several new possibilities of applications: (i) more stable optical clock than any current atomic clocks; (ii) sub-natural linewidth laser spectroscopy; (iii) long coherence time laser with linewidth at mHz level; (iv) Ramsey laser combining stimulated emission process and Ramsey separated oscillatory fields method," commented Professor Yiqiu Wang.
The coherence time describes the time varying nature of the channel in a small-scale region and is caused by the relative motion between the vehicles.
The ability to scale up both the atom number and coherence time will make this new-generation clock qualitatively different from the previous generation.