Related Experiment Video
Updated: May 22, 2026

Experimental Methods for Trapping Ions Using Microfabricated Surface Ion Traps
Published on: August 17, 2017
A low phase noise microwave source for atomic spin squeezing experiments in 87Rb
Zilong Chen1, Justin G Bohnet, Joshua M Weiner
1JILA, National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA.
Abstract:
We describe and characterize a simple, low cost, low phase noise microwave source that operates near 6.800 GHz for agile, coherent manipulation of ensembles of (87)Rb. Low phase noise is achieved by directly multiplying a low phase noise 100 MHz crystal to 6.8 GHz using a nonlinear transmission line and filtering the output with custom band-pass filters. The fixed frequency signal is single sideband modulated with a direct digital synthesis frequency source to provide the desired phase, amplitude, and frequency control. Before modulation, the source has a single sideband phase noise near -140 dBc/Hz in the range of 10 kHz-1 MHz offset from the carrier frequency and -130 dBc/Hz after modulation. The resulting source is estimated to contribute added spin-noise variance 16 dB below the quantum projection noise level during quantum nondemolition measurements of the clock transition in an ensemble 7 × 10(5) (87)Rb atoms.
Related Concept Videos
Atomic Nuclei: Nuclear Spin State Population Distribution
Atomic Nuclei: Nuclear Relaxation Processes
Atomic Nuclei: Nuclear Spin
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Atomic Nuclei: Nuclear Spin State Overview
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
Atomic Nuclei: Magnetic Resonance

