Rydberg atoms aren't antennas. When modulated and then read out by the electrical field of a laser they can be used to infer the ambient electrical field at a arbitrary frequency over very, very narrow frequency bandwidths. This can be used to receive radio signals. But it's not very good at it and it's not an antenna. While the specific frequency can be tuned over a very large range the instantaneous bandwidth is still too narrow to actually receive anything but narrowband carrier (no modulation wings) and barely that.

These are physics tools for specific things, not general radio receivers for transmitted information.

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greenbit 2 days ago | parent | next [-]

Yes, what is really needed is a way to baseband a good swath of spectrum, e.g. in the neighborhood of 100MHz to 10GHz, so that conventional electronics can be used to study something more than simple low rate there/not-there activity. And conversely a way to modulate similar bandwidth onto arbitrary frequencies up in the THz region.

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parineum 2 days ago | parent | prev [-]

What's an antenna if not something that can receive radio signals?

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estimator7292 2 days ago | parent | next [-]

The same way an LED is not a solar panel. It will give you some voltage, but basically a rounding error above zero.

Antenna are about capturing energy over macro scale areas. This atom is measuring electromagnetic oscillation at a particular point in space. Technically you can recover a signal, but only a rounding error above the noise floor. It doesn't capture energy.

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hulitu 2 days ago | parent | prev [-]

> What's an antenna if not something that can receive radio signals?

>> the instantaneous bandwidth is still too narrow to actually receive anything but narrowband carrier

so it is a "useless" antenna.

	▲	mycall a day ago \| parent [-]
		Could it pick up a THz chirp signal?