衬底上的1254个电极的微结构化阵列已被配置为在衬底上方约25 $μ$ m处产生具有120 $μ$ m周期性的电场强度的局部最小值的阵列。通过向电极施加正弦变化的电势，可以使这些最小值沿着阵列平滑地移动。在低场条件下寻找量子态的极性分子可以被捕获在这些移动势阱中。最近，我们通过在衬底上方以恒定速度传输亚稳态CO分子来实验证明了这一点[Phys. Rev. Lett. 100（2008）153003]。在这里，我们概述和实验演示如何使用这种微结构阵列直接从分子束中减速极性分子。为此，当分子到达芯片上方时，需要打开正弦变化的电势，它们的频率需要及时降低，并且它们需要在分子再次离开芯片之前关闭。亚稳态CO分子从360 m/s的初始速度到低至240 m/s的最终速度的减速在5 cm长的电极阵列上方的15-35 mK深势阱中被证明。这对应于几乎$10^5$ $g$的减速，并且在该过程中从亚稳态CO分子中去除约85 cm $^{-1}$的动能。
英文摘要：
A microstructured array of 1254 electrodes on a substrate has been configured to generate an array of local minima of electric field strength with a periodicity of 120 $μ$m about 25 $μ$m above the substrate. By applying sinusoidally varying potentials to the electrodes, these minima can be made to move smoothly along the array. Polar molecules in low-field seeking quantum states can be trapped in these traveling potential wells. Recently, we experimentally demonstrated this by transporting metastable CO molecules at constant velocities above the substrate [Phys. Rev. Lett. 100 (2008) 153003]. Here, we outline and experimentally demonstrate how this microstructured array can be used to decelerate polar molecules directly from a molecular beam. For this, the sinusoidally varying potentials need to be switched on when the molecules arrive above the chip, their frequency needs to be chirped down in time, and they need to be switched off before the molecules leave the chip again. Deceleration of metastable CO molecules from an initial velocity of 360 m/s to a final velocity as low as 240 m/s is demonstrated in the 15-35 mK deep potential wells above the 5 cm long array of electrodes. This corresponds to a deceleration of almost $10^5$ $g$, and about 85 cm$^{-1}$ of kinetic energy is removed from the metastable CO molecules in this process.
A Stark decelerator is an effective tool for controlling motional degrees of freedom of polar molecules. Due to technical limitations, many of the current Stark decelerators focus on molecules in low-field-seeking quantum states and are built based on a fixed electrode size and spacing (type-A architecture). Here, we present an alternative method based on a different architecture, so-called type-B, with microstructured electrodes and a simpler electric field pulse timing with the prospect of producing cold, quasi-CW molecular beams. We demonstrate with simulations the feasibility of this metho…
Controlling rovibrational state populations of polar molecules in inhomogeneous electric fields of the Stark deceleration: molecular dynamics and quantum chemistry simulations
We report on the deceleration of a beam of SrF molecules from 290 to 120~m/s. Following supersonic expansion, the molecules in the $X^2Σ$ ($v=0$, $N=1$) low-field seeking states are trapped by the moving potential wells of a traveling-wave Stark decelerator. With a deceleration strength of 9.6 km/s$^2$ we have demonstrated the removal of 85 % of the initial kinetic energy in a 4 meter long modular decelerator. The absolute amount of kinetic energy removed is a factor 1.5 higher compared to previous Stark deceleration experiments. The demonstrated decelerator provides a novel tool for the creat…
High-voltage generation system for a traveling-wave Stark decelerator
Van Swinderen Institute for Particle Physics and Gravity, University of Groningen（格罗宁根大学范斯温德恩粒子物理与引力研究所）；Nikhef, National Institute for Subatomic Physics（荷兰国家亚原子物理研究所）
Metastable (1s)(2s) $^3{\rm S}_1$ helium atoms produced in a supersonic beam were excited to Rydberg-Stark states (with $n$ in the $27-30$ range) in a cryogenic environment and subsequently decelerated by, and trapped above, a surface-electrode decelerator. In the trapping experiments, the Rydberg atoms were brought to rest in 75~$μ$s and over a distance of 33~mm and kept stationary for times $t_{\mathrm{trap}}$ in the $0-525$~$μ$s range, before being re-accelerated for detection by pulsed field ionization. The use of a home-built valve producing short gas pulses with a duration of about 20~$μ…
Beams of helium atoms in Rydberg-Stark states with principal quantum number $n=48$ and electric dipole moments of 4600~D have been decelerated from a mean initial longitudinal speed of 2000~m/s to zero velocity in the laboratory-fixed frame-of-reference in the continuously moving electric traps of a transmission-line decelerator. In this process accelerations up to $-1.3\times10^{7}$~m/s$^2$ were applied, and changes in kinetic energy of $ΔE_{\mathrm{kin}}=1.3\times10^{-20}$~J ($ΔE_{\mathrm{kin}}/e = 83$~meV) per atom were achieved. Guided and decelerated atoms, and those confined in stationar…
Nitric oxide (NO) molecules initially traveling at 795 m/s in pulsed supersonic beams have been photoexcited to long-lived hydrogenic Rydberg-Stark states, decelerated and electrostatically trapped in a cryogenically cooled, chip-based transmission-line Rydberg-Stark decelerator. The decelerated and trapped molecules were detected $in$ $situ$ by pulsed electric field ionization. The operation of the decelerator was validated by comparison of the experimental data with the results of numerical calculations of particle trajectories. Studies of the decay of the trapped molecules on timescales up …
We report on the electrostatic trapping of neutral SrF molecules. The molecules are captured from a cryogenic buffer-gas beam source into the moving traps of a 4.5 m long traveling-wave Stark decelerator. The SrF molecules in $X^2Σ^+(v=0, N=1)$ state are brought to rest as the velocity of the moving traps is gradually reduced from 190 m/s to zero. The molecules are held for up to 50 ms in multiple electric traps of the decelerator. The trapped packets have a volume (FWHM) of 1 mm$^{3}$ and a velocity spread of 5(1) m/s which corresponds to a temperature of $60(20)$ mK. Our result demonstrates …
Trapping potentials and quantum gates for microwave-dressed Rydberg atoms on an atom chip
Freie Universität Berlin（柏林自由大学）；Center for Quantum Science and Technologies, FORTH（量子科学与技术中心，FORTH）；University of Crete（克里特大学）；German Research Center for Artificial Intelligence（德国人工智能研究中心）；Eberhard Karls Universität Tübingen（蒂宾根大学）
