Quantum Post-Selected Optomechanics

量子后选择光力学本研究涉及最近提出的一种方案，用于产生和检测光力学系统的量子态。该方案基于嵌套干涉仪和量子后选技术。考虑一个光子进入马赫-曾德干涉仪。光子在马赫-曾德干涉仪的一个臂上遇到光机械系统。如果光子没有成功地改变光机械系统的声子激发，光子将在干涉仪的一个特定输出中离开干涉仪。然而，在声子激发的罕见事件中，光子可以在干涉仪的第二输出处离开干涉仪。第二个输出中的光子检测将选择强光力学相互作用。将此方法与基于光延迟线的同一光子的第二干涉测量方法相结合，可以获得光机械系统的退相干信息。这种方法减轻了与以前测量宏观叠加的光学方案相关的几个挑战，并且只需要器件处于弱耦合状态。随着这一新方案的实施，结合光力学系统设计和制造的进步（基于石墨烯、氮化硅薄膜、氮化硼和碳纳米管技术的使用），有望在宏观尺度上测试量子力学方面取得重大进展。想象一下，在一场高尔夫比赛中，你可以进行数百万次重来，也就是所谓的“穆里根”，直到最后一杆进洞。“量子后选择光力学”的研究正是为了做到这一点。自从著名的Schrödinger猫思想实验以来，物理学家们一直试图在越来越大的系统中观察量子效应，以便更好地理解从量子到经典行为的转变。人们的兴趣特别集中在光机械系统上，这是一种可以由光推动的微小机械装置。然而，事实证明，设计一种所谓的“强耦合”装置是极其困难的，这种装置足够脆弱，可以被单个光子显著地推动。这项研究涉及一种发送许多单个光子的方法，然后，在事实发生后，只选择那些一杆进洞的事件，由于量子波动，推动是显著的。光子与机械装置相互作用后，与自身发生干涉，通常单向传播。只有当它确实给了设备一个量子运动（一杆进洞）时，它才会以另一种方式传播。这种后选择的方法应该使研究力学系统的量子动力学成为可能。

Quantum Post Selected OptomechanicsThis research deals with a recently proposed scheme for producing and detecting quantum states of an opto-mechanical system. The scheme is based on nested-interferometers and quantum post-selection techniques. Consider a photon entering a Mach-Zender interferometer. The photon encounters an optomechanical system in one arm of the Mach-Zender interferometer. If the photon does not succeed in changing the phonon excitation of the optomechanical system the photon will leave the interferometer in one specific output of the interferometer. However in the rare event of a phonon excitation the photon can leave the interferometer at the second output of the interferometer. Photon detection in this second output will post-select for a strong optomechanical interaction. Combining this with a second interferometry method for the same photon, based on optical delay lines, can yield information on the decoherence of the optomechanical system. This method relieves several of the challenges associated with previous optical schemes for measuring macroscopic superpositions, and only requires the devices to be in the weak coupling regime. With the implementation of this new scheme combined with advances in the design and fabrication of optomechanical systems (based on the use of Graphene, Silicon Nitride films, Boron Nitride and Carbon nanotube technology) it is expected that significant progress towards testing quantum mechanics at the macroscopic scale can be made.Photons take a quantum MulliganImagine a game of golf in which you are allowed millions of do-overs, so-called "Mulligans," until finally hitting that hole-in-one. This research on "Quantum Post Selected Optomechanics" aims precisely at doing this. Since the famous Schrödinger's Cat thought experiment, physicists have tried to observe quantum effects in larger and larger systems, in order to better understand the transition from quantum to classical behavior. In particular, interest has focused on optomechanical systems, tiny mechanical devices that can be pushed by light. However, it has proven extremely difficult to design a so-called "strongly coupled" device, one that is flimsy enough to be pushed significantly by a single photon. This research deals with a way to send many individual photons and then, after the fact, pick only those hole-in-one events where, thanks to a quantum fluctuation, the push was significant. After the interaction with the mechanical device, the photon interferes with itself, and usually travels one way. It only travels the other way if it has actually given a quantum of motion to the device (a hole-in-one). This method of post-selection should enable the study of quantum dynamics of mechanical systems.