论文标题
空间延伸离子晶体的运动加热
Motional heating of spatially extended ion crystals
论文作者
论文摘要
我们研究了单个离子和延伸离子晶体的加热，该晶体被困在线性射频（RF）Paul陷阱中，精度为$δ\ dot {\ bar {n}}} \大约0.2 $ phonons s $^{ - 1} $。单离子轴向和径向加热率是一致的，并且在四年的时间里，电场噪声一直稳定。 At a secular frequency of $ω_\mathrm{sec}=2π\times620$ kHz, we measure $\dot{\bar{n}} = 0.56(6)$ phonons s$^{-1}$ per ion for the center-of-mass (com) mode of linear chains of up to eleven ions and observe no significant heating of the out-of-phase (oop)模式。通过使离子脱离淋巴结线，诱导过量的微功能，rf噪声将COM模式加热为radial位移$ r $ by $ \ dot {\ bar {n}}（r）/ r）/ r^2 = 0.89（4）$ phonons s $^$^$^$^$^$^$^$^ - $^$^ - $^$^ - $^$^ - 2受保护，免受线性链中的RF噪声诱导加热。通过将谐振RF电路的质量因子从$ Q = 542 $更改为$ Q = 204 $，我们观察到RF噪声的增加增加了3个。我们表明，RF噪声诱导的延伸晶体的运动模式的加热也取决于晶体的对称性和模式本身。例如，我们考虑几种2D和3D晶体配置。对于单个模式，观察到高达500个声子S $^{ - 1} $的加热速率，从而导致总系统的总体时间扩张的总成分，从而使总系统的分数扩张转移高达$ -0.3 \ times 10^{ - 18} $ s $ s $^{ - 1} $。此外，我们详细介绍了如何降低单个离子的激发概率，并且由于Debye-Waller效应而增加了脱碳。
We study heating of motional modes of a single ion and of extended ion crystals trapped in a linear radio frequency (rf) Paul trap with a precision of $Δ\dot{\bar{n}} \approx 0.2 $ phonons s$^{-1}$. Single-ion axial and radial heating rates are consistent and electric field noise has been stable over the course of four years. At a secular frequency of $ω_\mathrm{sec}=2π\times620$ kHz, we measure $\dot{\bar{n}} = 0.56(6)$ phonons s$^{-1}$ per ion for the center-of-mass (com) mode of linear chains of up to eleven ions and observe no significant heating of the out-of-phase (oop) modes. By displacing the ions away from the nodal line, inducing excess micromotion, rf noise heats the com mode quadratically as a function of radial displacement $r$ by $\dot{\bar{n}}(r)/ r^2 = 0.89(4)$ phonons s$^{-1}$ $μ$m$^{-2}$ per ion, while the oop modes are protected from rf-noise induced heating in linear chains. By changing the quality factor of the resonant rf circuit from $Q=542$ to $Q=204$, we observe an increase of rf noise by a factor of up to 3. We show that the rf-noise induced heating of motional modes of extended crystals also depends on the symmetry of the crystal and of the mode itself. As an example, we consider several 2D and 3D crystal configurations. Heating rates of up to 500 phonons s$^{-1}$ are observed for individual modes, giving rise to a total kinetic energy increase and thus a fractional time dilation shift of up to $-0.3\times 10^{-18}$ s$^{-1}$ of the total system. In addition, we detail on how the excitation probability of the individual ions is reduced and decoherence is increased due to the Debye-Waller effect.
