Related Experiment Video
Updated: Jul 23, 2025
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
7.5K
Dynamical low-noise microwave source for cold-atom experiments
Bernd Meyer-Hoppe1, Maximilian Baron1, Christophe Cassens1
1Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, D-30167 Hannover, Germany.
The Review of Scientific Instruments
|July 17, 2023
Summary
We developed a low-noise microwave source for quantum experiments. This source offers precise control over frequency, amplitude, and phase, enabling advanced techniques for ultracold atoms.
Area of Science:
- Quantum physics
- Atomic physics
- Microwave engineering
Background:
- Precise control of ultracold atoms requires low-noise microwave fields.
- Existing microwave sources often lack the dynamic control needed for advanced quantum manipulation.
Purpose of the Study:
- To present a novel low-phase-noise microwave source with dual, independently controllable output paths.
- To enable dynamic control of microwave fields for quantum regime applications.
Main Methods:
- Combining an ultra-low-noise 7 GHz oscillator with a direct digital frequency synthesizer.
- Utilizing two commercially available frequency synthesizers for flexible signal generation.
- Implementing fast frequency, amplitude, and phase updates within sub-microsecond timescales.
Main Results:
- Achieved a low integrated phase noise of 480 µrad (10 Hz to 100 kHz).
- Demonstrated independent control over two microwave output paths operating at 6.835 GHz ± 25 MHz.
- Enabled rapid signal modulation for shaped pulse generation.
Conclusions:
- The developed microwave source meets the stringent requirements for manipulating ultracold atomic ensembles.
- Its dynamic control capabilities facilitate the implementation of advanced quantum control techniques, such as composite pulses.
- This technology advances the precision and flexibility of experiments in quantum atomic physics.
Related Concept Videos
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
1.0K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
1.0K
01:25Atomic Absorption Spectroscopy: Atomization Methods
587
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the...
587
01:05Atomic Nuclei: Magnetic Resonance
689
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
689
01:27Atomic Spectroscopy: Effects of Temperature
370
Atomization, converting samples into gas-phase atoms and ions, is essential for atomic spectroscopy. The flame temperature required for atomization affects the efficiency of the atomic spectroscopic methods by increasing the atomization efficiency and the relative population of the excited and ground states.
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature...
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature...
370
01:23Atomic Nuclei: Nuclear Relaxation Processes
683
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
683
01:11Atomic Nuclei: Larmor Precession Frequency
1.5K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
1.5K