Müller M, Vural H, Schneider C, Rastelli A, Schmidt O G, Höfling S, Michler P
Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and SCoPE, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
Technische Physik and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Physikalisches Institut, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Phys Rev Lett. 2017 Jun 23;118(25):257402. doi: 10.1103/PhysRevLett.118.257402. Epub 2017 Jun 22.
Multiphoton entangled states such as "N00N states" have attracted a lot of attention because of their possible application in high-precision, quantum enhanced phase determination. So far, N00N states have been generated in spontaneous parametric down-conversion processes and by mixing quantum and classical light on a beam splitter. Here, in contrast, we demonstrate superresolving phase measurements based on two-photon N00N states generated by quantum dot single-photon sources making use of the Hong-Ou-Mandel effect on a beam splitter. By means of pulsed resonance fluorescence of a charged exciton state, we achieve, in postselection, a quantum enhanced improvement of the precision in phase uncertainty, higher than prescribed by the standard quantum limit. An analytical description of the measurement scheme is provided, reflecting requirements, capability, and restraints of single-photon emitters in optical quantum metrology. Our results point toward the realization of a real-world quantum sensor in the near future.
诸如“N00N态”之类的多光子纠缠态因其在高精度、量子增强相位测定中的潜在应用而备受关注。到目前为止，N00N态已在自发参量下转换过程中以及通过在分束器上混合量子光和经典光而产生。相比之下，在这里我们展示了基于量子点单光子源产生的双光子N00N态的超分辨相位测量，该测量利用了分束器上的Hong-Ou-Mandel效应。通过带电激子态的脉冲共振荧光，我们在后选择中实现了相位不确定性精度的量子增强改善，高于标准量子极限规定的值。提供了测量方案的解析描述，反映了光学量子计量中单光子发射器的要求、能力和限制。我们的结果表明在不久的将来有望实现实际的量子传感器。
