Recent results of the searches for Supersymmetry in final states with one or two leptons at CMS are presented. Many Supersymmetry scenarios, including the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM), predict a substantial amount of events containing leptons, while the largest fraction of Standard Model background events -which are QCD interactions -gets strongly reduced by requiring isolated leptons. The analyzed data was taken in 2011 and corresponds to an integrated luminosity of approximately L = 1 fb −1 . The center-of-mass energy of the pp collisions was √ s = 7 TeV.

The ability to sensitively detect individual charges under ambient conditions would benefit a wide range of applications across disciplines. However, most current techniques are limited to low-temperature methods such as single-electron transistors 1,2 , single-electron electrostatic force microscopy 3 and scanning tunnelling microscopy 4 . Here we introduce a quantum-metrology technique demonstrating precision three-dimensional electric-field measurement using a single nitrogen-vacancy defect centre spin in diamond. An a.c. electric-field sensitivity reaching 202 ± 6 V cm −1 Hz −1/2 has been achieved. This corresponds to the electric field produced by a single elementary charge located at a distance of ∼150 nm from our spin sensor with averaging for one second. The analysis of the electronic structure of the defect centre reveals how an applied magnetic field influences the electric-field-sensing properties. We also demonstrate that diamond-defect-centre spins can be switched between electric-and magnetic-field sensing modes and identify suitable parameter ranges for both detector schemes. By combining magnetic-and electric-field sensitivity, nanoscale detection and ambient operation, our study should open up new frontiers in imaging and sensing applications ranging from materials science to bioimaging.Sensitive imaging or detection of charges is an outstanding task in a variety of applications. The development, for example, of single-electron transistors (SET; ref. 5) has pushed charge sensing to an unprecedented sensitivity of 10 −6 electron charge, and is being used in low-temperature detection and scanning applications 2 , and in sensors in quantum devices 6 . Inspired by the development of tunnelling microscopy a variety of scanning probes have been devised to measure surface electrical properties, such as scanning capacitance microscopy (SCM; ref. 7), scanning Kelvin probe (ref. 8) and electric field-sensitive atomic force microscopy (EFM; ref. 9). Indeed, the last method has shown the remarkable ability to detect the presence of individual charges 3 .We report on a fundamentally new method that uses the spin of single defect centres in diamond to sense electric-field-dependent shifts in energy levels. Sensitive electric-field detection is based on the remarkable properties of the NV centre 10 . The most notable of these are: the detection of fluorescence from single defects to provide an atom-sized local probe 11 , outstandingly long spin dephasing times 12 , as well as the controlled positioning of single centres 13,14 . These properties have led to a variety of applications of the NV centre, ranging from quantum science 15 and precision magnetic-field sensing [16][17][18][19][20][21][22][23][24] to biolabelling 25,26 . It is the aim of the present work to explore the interplay between the Zeeman shift, local strain effects and the Stark shift of the ground state spin manifold and use the improved understanding of this interplay for the sensing of electric fields. We will show that the decoupling of the...

We report strong coupling between an ensemble of nitrogen-vacancy center electron spins in diamond and a superconducting microwave coplanar waveguide resonator. The characteristic scaling of the collective coupling strength with the square root of the number of emitters is observed directly. Additionally, we measure hyperfine coupling to (13)C nuclear spins, which is a first step towards a nuclear ensemble quantum memory. Using the dispersive shift of the cavity resonance frequency, we measure the relaxation time of the NV center at millikelvin temperatures in a nondestructive way.

Physics and information are intimately connected, and the ultimate information processing devices will be those that harness the principles of quantum mechanics. Many physical systems have been identified as candidates for quantum information processing, but none of them are immune from errors. The challenge remains to find a path from the experiments of today to a reliable and scalable quantum computer. Here, we develop an architecture based on a simple module comprising an optical cavity containing a single negatively charged nitrogen vacancy center in diamond. Modules are connected by photons propagating in a fiber-optical network and collectively used to generate a topological cluster state, a robust substrate for quantum information processing. In principle, all processes in the architecture can be deterministic, but current limitations lead to processes that are probabilistic but heralded. We find that the architecture enables large-scale quantum information processing with existing technology.