Related papers: Sympathetic ground state cooling and coherent mani…
We report quantum ground state cooling of a levitated nanoparticle in a room temperature environment. Using coherent scattering into an optical cavity we cool the center of mass motion of a $143$ nm diameter silica particle by more than $7$…
Dense arrays of trapped ions provide one way of scaling up ion trap quantum information processing. However, miniaturization of ion traps is currently limited by sharply increasing motional state decoherence at sub-100 um ion-electrode…
Cold ions in traps are well-established, highly controllable quantum systems with a wide variety of applications in quantum information, precision spectroscopy, clocks and chemistry. Nanomechanical oscillators are used in advanced sensing…
Atomic ions, confined in radio-frequency Paul ion traps, are a promising candidate to host a future quantum information processor. In this letter, we demonstrate a method to couple two motional modes of a single trapped ion, where the…
Efficient high-fidelity ground-state cooling of motional degrees of freedom is crucial for applications in quantum simulation, computing and metrology. Here, we demonstrate direct ground-state cooling of fermionic $^{171}$Yb and bosonic…
We demonstrate millikelvin thermometry of laser cooled trapped ions with high-resolution imaging. This equilibrium approach is independent of the cooling dynamics and has lower systematic error than Doppler thermometry, with \pm5 mK…
We demonstrate the Doppler laser cooling of $^{40}$Ca$^+$ ions confined in a segmented linear Paul trap in the presence of a strong quadrupolar magnetic field generated by two permanent ring magnets. Magnetic field gradients of 800 to 1600…
We consider a possible route to ground state cooling of a levitated nanoparticle, magnetically trapped by a strong permanent magnet, using a combination of measurement and feedback. The trap frequency of this system is much lower than those…
We demonstrate simple and robust methods for Doppler cooling and obtaining high fluorescence from trapped 43Ca+ ions at a magnetic field of 146 Gauss. This field gives access to a magnetic-field-independent "atomic clock" qubit transition…
Cooling to the motional ground state is an important first step in the preparation of nonclassical states of mesoscopic mechanical oscillators. Light-mediated coupling to a remote atomic ensemble has been proposed as a method to reach the…
Levitated particles are an ideal tool for measuring weak forces and investigating quantum mechanics in macroscopic objects. Arrays of two or more of these particles have been suggested for improving force sensitivity and entangling…
We propose a scheme for generating steady entanglement between two distant atomic qubits in the coupled-cavity system via laser cooling. With suitable choice of the laser frequencies, the target entangled state is the only ground state that…
We study the thermodynamical properties of crystals of trapped ions which are laser cooled to two different temperatures in two separate regions. We show that these properties strongly depend on the structure of the ion crystal. Such…
In recent demonstrations of the quantum charge-coupled device (QCCD) computer architecture, circuit times are dominated by cooling. Some motional modes of multi-ion crystals take orders-of-magnitude longer to cool than others because of low…
Individual electrodynamically trapped and laser cooled ions are addressed in frequency space using radio-frequency radiation in the presence of a static magnetic field gradient. In addition, an interaction between motional and spin states…
We show how a conditional displacement of the vibrational mode of trapped ions can be used to simulate nonlinear collective and interacting spin systems including nonlinear tops and Ising models (a universal two qubit gate), independent of…
We combine near--deterministic preparation of a single atom with Raman sideband cooling, to create a push button mechanism to prepare a single atom in the motional ground state of tightly focused optical tweezers. In the 2D radial plane, we…
We demonstrate the implementation of a spin qubit with a single Ca ion in a micro ion trap. The qubit is encoded in the Zeeman ground state levels mJ=+1/2 and mJ=-1/2 of the S1/2 state of the ion. We show sideband cooling close to the…
We demonstrate a spatial-imaging thermometry technique for ions in a one-dimensional Coulomb crystal by relating their imaged spatial extent along the linear radiofrequency ion trap axis to normal modes of vibration of coupled oscillators…
We discuss a laser cooling scheme for trapped atoms or ions which is based on double electromagnetically induced transparency (EIT) and makes use of a four-level atom in tripod configuration. The additional fourth atomic state is coupled by…