arXiv subjects

C. Tuchendler

Publications and source records attributed to C. Tuchendler.

5 recordsLinked to original sources

arXiv2010

Imaging a single atom in a time-of-flight experiment

We perform fluorescence imaging of a single 87Rb atom after its release from an optical dipole trap. The time-of-flight expansion of the atomic spatial density distribution is observed by accumulating many single atom images. The position of the atom is revealed with a spatial resolution close to 1 micrometer by a single photon event, induced by a short resonant probe. The expansion yields a measure of the temperature of a single atom, which is in very good agreement with the value obtained by an independent measurement based on a release-and-recapture method. The analysis presented in this paper provides a way of calibrating an imaging system useful for experimental studies involving a few atoms confined in a dipole trap.

cond-mat.quant-gas↗

arXiv2008

Energy distribution and cooling of a single atom in an optical tweezer

We investigate experimentally the energy distribution of a single rubidium atom trapped in a strongly focused dipole trap under various cooling regimes. Using two different methods to measure the mean energy of the atom, we show that the energy distribution of the radiatively cooled atom is close to thermal. We then demonstrate how to reduce the energy of the single atom, first by adiabatic cooling, and then by truncating the Boltzmann distribution of the single atom. This provides a non-deterministic way to prepare atoms at low microKelvin temperatures, close to the ground state of the trapping potential.

quant-ph↗

arXiv2007

Recent progress on the manipulation of single atoms in optical tweezers for quantum computing

This paper summarizes our recent progress towards using single rubidium atoms trapped in an optical tweezer to encode quantum information. We demonstrate single qubit rotations on this system and measure the coherence of the qubit. We move the quantum bit over distances of tens of microns and show that the coherence is reserved. We also transfer a qubit atom between two tweezers and show no loss of coherence. Finally, we describe our progress towards conditional entanglement of two atoms by photon emission and two-photon interferences.

quant-ph↗

arXiv2007

Two-dimensional transport and transfer of a single atomic qubit in optical tweezers

Quantum computers have the capability of out-performing their classical counterparts for certain computational problems. Several scalable quantum computing architectures have been proposed. An attractive architecture is a large set of physically independant qubits, arranged in three spatial regions where (i) the initialized qubits are stored in a register, (ii) two qubits are brought together to realize a gate, and (iii) the readout of the qubits is performed. For a neutral atom-based architecture, a natural way to connect these regions is to use optical tweezers to move qubits within the system. In this letter we demonstrate the coherent transport of a qubit, encoded on an atom trapped in a sub-micron tweezer, over a distance typical of the separation between atoms in an array of optical traps. Furthermore, we transfer a qubit between two tweezers, and show that this manipulation also preserves the coherence of the qubit.

quant-ph↗

arXiv2006

Diffraction limited optics for single atom manipulation

We present an optical system designed to capture and observe a single neutral atom in an optical dipole trap, created by focussing a laser beam using a large numerical aperture N.A.=0.5 aspheric lens. We experimentally evaluate the performance of the optical system and show that it is diffraction limited over a broad spectral range (~ 200 nm) with a large transverse field (+/- 25 microns). The optical tweezer created at the focal point of the lens is able to trap single atoms of 87Rb and to detect them individually with a large collection efficiency. We measure the oscillation frequency of the atom in the dipole trap, and use this value as an independent determination of the waist of the optical tweezer. Finally, we produce with the same lens two dipole traps separated by 2.2 microns and show that the imaging system can resolve the two atoms.

quant-ph↗