Ultracold Deterministic Ion Source Targeting the Heisenberg Limit
Dr. Kilian Singer (Universität Mainz)

<p> The major challenges to fabricate solid state quantum processors and future nano-solid-state devices are material modification techniques with nanometer resolution and suppression of statistical fluctuations of dopants or qubit carriers. Based on a segmented ion trap with mK laser-cooled ions, we have realized a deterministic single-ion source, which could operate with a huge range of sympathetically cooled ion species, isotopes or ionic molecules
[1]. By using an electrostatic einzel-lens, we focus down an ion beam consisting of single Calcium ions by a factor 12 [2]. Due to the small beam divergence and narrow velocity distribution of our ion source, chromatic and spherical aberration at the einzel-lens is vastly reduced, presenting a promising starting point for focusing single ions on their way to a substrate. Numerical simulations predict, that if the ions are cooled to the motional ground state (Heisenberg limit), nanometer spatial resolution can be achieved [2,3]. This technique can e.g. be applied to generate color centers in diamond or to implant P into Si. Both systems provide a possible way for the realization of a solid state quantum computer [4,5]. Another challenge is to circumvent the breakdown of More's law due to Poissonian dopant fluctuations in nanometer scaled semiconductor devices where deterministic implantation of single ions can greatly enhance the electrical properties[6]. <p>

<p> [1] W. Schnitzler et al., Phys. Rev. Lett. 102, 070501 (2009). <p>

<p> [2] W. Schnitzler et al., quant-ph/0912.1258v2, accepted for publication in NJP. <p>

<p> [3] R. Fickler et al., Journal of Modern Optics 56, 2061 (2009). <p>

<p> [4] F. Jelezko et al., Physica Status Solidi A 203, 3207 (2006). <p>

<p> [5] B. Kane, Nature 393, 133 (1998). <p>

<p> [6] T. Shinada et al., Nature 437, 1128 (2005). <p>