We experimentally demonstrate coupling of an atomically thin, free-standing graphene membrane to an optical cavity. By changing the position of the membrane along the standing-wave field of the cavity we tailor the dissipative coupling between the membrane and the cavity, and we show that the dissipative coupling can outweigh the dispersive coupling. Such a system, for which controlled dissipation prevails dispersion, will prove useful for novel laser-cooling schemes in optomechanics. In addition, we have determined the continuouswave optical damage threshold of free-standing monolayer graphene of 1.8(4) MW/cm 2 at 780nm.The coupling between light and matter is a fundamental ingredient for many applications ranging from highly precise detection of mechanical motion [1,2] to quantum information science [3]. Accurate control over the amplitude and phase of the coupling requires precise localization of the matter relative to the light field. Such control has been experimentally demonstrated using microscopic, point-like physical systems such as single atoms [4], trapped ions [5,6], gold nanoparticles [7], semiconductor quantum dots [8] and NV centers in diamond [9]. Additionally, macroscopic objects, such as SiN membranes have been coupled locally to standing-wave light fields [10,11]. They combine low absorption and high dispersion with very good handling, and they have been used, for example, in optomechanical experiments [12] in which the motion-dependent interaction between the membrane and a light field is studied.Advances in the fabrication of two-dimensional materials, like graphene [13], have made it possible to fabricate atomically thin membranes, which combine the ease of use of macroscopic membranes with the positioning accuracy of a single atom. Owing to their low mass and high stiffness they promise higher vibrational frequencies [14,15] than SiN membranes, which is of great interest for future graphene-based optomechanical applications. Another key difference between membranes made of graphene and those made of SiN is the nature of the light-matter coupling. While for SiN membranes the coupling is dispersive, for graphene membranes it has been predicted to be mostly dissipative since a monolayer of graphene exhibits a single-pass absorption of A ≈ πα = 2.3% in the optical range [16]. Hence, a graphene membrane will cause a position-dependent dissipation of the intra-cavity field, which is wavelengthindependent within the visible to near infra-red spectral range. In contrast to standard dispersive optomechanical coupling [12], a predominantly dissipative coupling between membrane and cavity field could allow for efficient laser cooling of the membrane's motion even outside the resolved sideband regime [17,18].Recently, graphene has been optomechanically coupled to superconducting microwave cavities [15] and to the evanescent field of an optical microsphere-resonator [19], however, in both cases the spatial structure of the electromagnetic field was not resolved in the coupling. Here we present...

The development of efficient network nodes is a key element for the realization of quantum networks which promise great capabilities as distributed quantum computing or provable secure communication. We report the realization of a quantum network node using a trapped ion inside a fiber-based Fabry–Perot cavity. We show the generation of deterministic entanglement at a high fidelity of 90.1(17)% between a trapped Yb ion and a photon emitted into the resonator mode. We achieve a success probability for generation and detection of entanglement for a single shot of 2.5 × 10−3 resulting in 62 Hz entanglement rate.

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Cold atom experiments commonly use broad magnetic Feshbach resonances to manipulate the interaction between atoms. In order to induce quantum dynamics by a change in the interaction strength, rapid (∼μs) magnetic field changes over several tens of Gauss are required. Here, we present a compact design of a coil and its control circuit for a change in the magnetic field up to 36 G in 3 µs. The setup comprises two concentric solenoids with minimal space requirements, which can be readily added to existing apparatuses. This design makes the observation of non-equilibrium physics with broad Feshbach resonances accessible.

We experimentally demonstrate coupling of an atomically thin, free-standing graphene membrane to an optical cavity. By changing the position of the membrane along the standing-wave field of the cavity we tailor the dissipative coupling between the membrane and the cavity, and we show that the dissipative coupling can outweigh the dispersive coupling. Such a system, for which controlled dissipation prevails dispersion, will prove useful for novel laser-cooling schemes in optomechanics. In addition, we have determined the continuouswave optical damage threshold of free-standing monolayer graphene of 1.8(4) MW/cm 2 at 780nm. arXiv:1606.07897v1 [physics.optics]