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The created Mg ions are trapped and cooled. This makes it possible to built 2D Coulomb crystals, which are used for subsequent measurements.
The group’s experimental work builds on trapped ion systems and aims (i) to gain deeper insight into complex dynamics that are influenced or even driven by quantum effects, and (ii) to control individual atoms and molecules at the highest level possible to set up manybody (model) systems. Additionally, we are exploring to combine optical traps for ions and neutral atoms [1]. Last year we demonstrated a sensitive high-resolution laser spectroscopy method building on quantum effects [2].
Common bottlenecks in all of our projects are the demanding requirements on laser systems for preparation and controlling internal and external degrees of freedom of ions. Thus our work greatly depends on innovative laser technologies that are user friendly and can be used as versatile tools to work with a variety of atomic species, isotopes, and their combination.
THE PROJECT
Topologically protected defects within Coulomb crystals can be suitable to simulate discrete solitons. During the process of crystallization, a system will seek for perfect order (minimal energy). By evolving the phase transition too fast for communication between different sections of the crystal, sub-ensembles find perfect crystalline order, while becoming incommensurate at their borders; these defects can oscillate as trapped quasi particles in their selfinduced confining potential within the crystal [3, 4].
In order to study these defects we load ten to fifty ions into our conventional RF trap via photo ionizing a thermal beam of magnesium atoms within the trapping region. It is required to load an isotopically pure crystal from an oven that is filled with natural abundant magnesium isotopes (79% of 24Mg, 10% of 25Mg, and 11% of 26Mg).
We can selectively load different isotopes as we ionize the atoms via a two photon process (Fig.2). The first step resonantly drives an electric dipole transition in the neutral magnesium, while the second non-resonant step ionizes the atoms. Due to the mass dependent frequency shift of this first transition at around 285.3 nm, we can individually address the three different isotopes [5]. By exciting the ions at around 279.6 nm we record the fluorescence light of the individual ions on a CCD camera (yielding images as shown in Fig. 1).
UTILIZING THE C-WAVE
In the present experiment the C-WAVE system is used for the photoionization step. Light at 570.6 nm is fibre coupled (coupling efficiency greater than 70 %) and sent to a homebuilt second-harmonic generation (SHG) external ring cavity using a BBO crystal to convert the VIS to the UV (285.3 nm), see Fig. 3. The UV output beam (a few mW) of the SHG stage is superimposed with a second UV beam at 279.6 nm (generated by a different laser system). Both are guided free-space to an ultra-high-vacuum chamber where the trap is mounted.
The beams are collimated with the central trapping region. Here the first beam ionizes the neutral magnesium atoms while the second Doppler cools the trapped ions into a crystalline structure. The ions are trapped in a combined rf and dc confinement potential. To ensure the isotopically enhanced ion loading, a fraction of the C-WAVE output light is send to an Iodine Doppler-free saturation spectroscopy setup, see part of Fig. 3. This setup is used as an absolute frequency reference and enables accurate tuning of the C-WAVE.
A recorded 1f spectrum around 570.6 nm is shown in Fig. 4 and agrees within a few MHz with a simulated spectrum [6].
The C-WAVE system is fully integrated into our experiment with trapped ions. Due to its wide tuning range from 450-650 nm, its demonstrated narrow linewidth < 1 MHz, and the high output in the 0.5 W range, C-WAVE is a flexible CW laser light source, well suited for various applications in spectroscopy and quantum optic experiments. confinement potential. To ensure the isotopically enhanced ion loading, a fraction of the C-WAVE output light is send to an Iodine Doppler-free saturation spectroscopy setup, see part of Fig. 3. This setup is used as an absolute frequency reference and enables accurate tuning of the C-WAVE. A recorded 1f spectrum around 570.6 nm is shown in Fig. 4 and agrees within a few MHz with a simulated spectrum [6]. The C-WAVE system is fully integrated into our experiment with trapped ions. Due to its wide tuning range from 450-650 nm, its demonstrated narrow linewidth < 1 MHz, and the high output in the 0.5 W range, C-WAVE is a flexible CW laser light source, well suited for various applications in spectroscopy and quantum optic experiments.
Common bottlenecks in all of our projects are the demanding requirements on laser systems for preparation and controlling internal and external degrees of freedom of ions. Thus our work greatly depends on innovative laser technologies that are user friendly and can be used as versatile tools to work with a variety of atomic species, isotopes, and their combination.
THE PROJECT
Topologically protected defects within Coulomb crystals can be suitable to simulate discrete solitons. During the process of crystallization, a system will seek for perfect order (minimal energy). By evolving the phase transition too fast for communication between different sections of the crystal, sub-ensembles find perfect crystalline order, while becoming incommensurate at their borders; these defects can oscillate as trapped quasi particles in their selfinduced confining potential within the crystal [3, 4].
In order to study these defects we load ten to fifty ions into our conventional RF trap via photo ionizing a thermal beam of magnesium atoms within the trapping region. It is required to load an isotopically pure crystal from an oven that is filled with natural abundant magnesium isotopes (79% of 24Mg, 10% of 25Mg, and 11% of 26Mg).
We can selectively load different isotopes as we ionize the atoms via a two photon process (Fig.2). The first step resonantly drives an electric dipole transition in the neutral magnesium, while the second non-resonant step ionizes the atoms. Due to the mass dependent frequency shift of this first transition at around 285.3 nm, we can individually address the three different isotopes [5]. By exciting the ions at around 279.6 nm we record the fluorescence light of the individual ions on a CCD camera (yielding images as shown in Fig. 1).
UTILIZING THE C-WAVE
In the present experiment the C-WAVE system is used for the photoionization step. Light at 570.6 nm is fibre coupled (coupling efficiency greater than 70 %) and sent to a homebuilt second-harmonic generation (SHG) external ring cavity using a BBO crystal to convert the VIS to the UV (285.3 nm), see Fig. 3. The UV output beam (a few mW) of the SHG stage is superimposed with a second UV beam at 279.6 nm (generated by a different laser system). Both are guided free-space to an ultra-high-vacuum chamber where the trap is mounted.
The beams are collimated with the central trapping region. Here the first beam ionizes the neutral magnesium atoms while the second Doppler cools the trapped ions into a crystalline structure. The ions are trapped in a combined rf and dc confinement potential. To ensure the isotopically enhanced ion loading, a fraction of the C-WAVE output light is send to an Iodine Doppler-free saturation spectroscopy setup, see part of Fig. 3. This setup is used as an absolute frequency reference and enables accurate tuning of the C-WAVE.
A recorded 1f spectrum around 570.6 nm is shown in Fig. 4 and agrees within a few MHz with a simulated spectrum [6].
The C-WAVE system is fully integrated into our experiment with trapped ions. Due to its wide tuning range from 450-650 nm, its demonstrated narrow linewidth < 1 MHz, and the high output in the 0.5 W range, C-WAVE is a flexible CW laser light source, well suited for various applications in spectroscopy and quantum optic experiments. confinement potential. To ensure the isotopically enhanced ion loading, a fraction of the C-WAVE output light is send to an Iodine Doppler-free saturation spectroscopy setup, see part of Fig. 3. This setup is used as an absolute frequency reference and enables accurate tuning of the C-WAVE. A recorded 1f spectrum around 570.6 nm is shown in Fig. 4 and agrees within a few MHz with a simulated spectrum [6]. The C-WAVE system is fully integrated into our experiment with trapped ions. Due to its wide tuning range from 450-650 nm, its demonstrated narrow linewidth < 1 MHz, and the high output in the 0.5 W range, C-WAVE is a flexible CW laser light source, well suited for various applications in spectroscopy and quantum optic experiments.
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