An average filling factor of one atom per lattice site has been obtained in a submicron scale far-off-resonance optical lattice (FORL). High site occupation is obtained through a compression sequence that includes laser cooling in a 3D FORL and adiabatic toggling between the 3D FORL and a 1D FORL trap. After the highest filling factor is achieved, laser cooling causes collisional loss from lattice sites with more than one atom. Ultimately $44%$ of the sites have a single atom cooled to near its vibrational ground state. A theoretical model of site occupation based on Poisson statistics agrees well with the experimental results.An average filling factor of one atom per lattice site has been obtained in a submicron scale far-off-resonance optical lattice (FORL). High site occupation is obtained through a compression sequence that includes laser cooling in a 3D FORL and adiabatic toggling between the 3D FORL and a 1D FORL trap. After the highest filling factor is achieved, laser cooling causes collisional loss from lattice sites with more than one atom. Ultimately $44%$ of the sites have a single atom cooled to near its vibrational ground state. A theoretical model of site occupation based on Poisson statistics agrees well with the experimental results.

Physical Review LettersMar 15, 1999170 citations

Scalability of quantum computation with addressable optical lattices

Travis Roland Beals, Jiří Vala, K. Birgitta Whaley

We make a detailed analysis of error mechanisms, gate fidelity, and scalability of proposals for quantum computation with neutral atoms in addressable (large lattice constant) optical lattices. We have identified possible limits to the size of quantum computations, arising in three-dimensional (3D) optical lattices from current limitations on the ability to perform single-qubit gates in parallel and in 2D lattices from constraints on laser power. Our results suggest that 3D arrays as large as $100\ifmmode\times\else\texttimes\fi{}100\ifmmode\times\else\texttimes\fi{}100$ sites (i.e., $\ensuremath{\sim}{10}^{6}$ qubits) may be achievable, provided two-qubit gates can be performed with sufficiently high precision and degree of parallelizability. The parallelizability of long-range interaction-based two-qubit gates is qualitatively compared to that of collisional gates. Different methods of performing single-qubit gates are compared, and a lower bound of $1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ is determined on the error rate for the error mechanisms affecting $^{133}\text{C}\text{s}$ in a blue-detuned lattice with Raman-transition-based single-qubit gates, given reasonable limits on experimental parameters.We make a detailed analysis of error mechanisms, gate fidelity, and scalability of proposals for quantum computation with neutral atoms in addressable (large lattice constant) optical lattices. We have identified possible limits to the size of quantum computations, arising in three-dimensional (3D) optical lattices from current limitations on the ability to perform single-qubit gates in parallel and in 2D lattices from constraints on laser power. Our results suggest that 3D arrays as large as $100\ifmmode\times\else\texttimes\fi{}100\ifmmode\times\else\texttimes\fi{}100$ sites (i.e., $\ensuremath{\sim}{10}^{6}$ qubits) may be achievable, provided two-qubit gates can be performed with sufficiently high precision and degree of parallelizability. The parallelizability of long-range interaction-based two-qubit gates is qualitatively compared to that of collisional gates. Different methods of performing single-qubit gates are compared, and a lower bound of $1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ is determined on the error rate for the error mechanisms affecting $^{133}\text{C}\text{s}$ in a blue-detuned lattice with Raman-transition-based single-qubit gates, given reasonable limits on experimental parameters.

arXiv:0804.1971Physical Review AMay 7, 200816 citations

Signatures of single-site addressability in resonance fluorescence spectra

Peter Degenfeld-Schonburg, Elena del Valle, Michael J. Hartmann

Pioneering methods in recent optical-lattice experiments allow focusing laser beams down to a spot size that is comparable to the lattice constant. Inspired by this achievement, we examine the resonance fluorescence spectra of two-level atoms positioned in adjacent lattice sites and compare the case where the laser hits only one atom (single-site addressing) with cases where several atoms are illuminated. In contrast to the case where the laser hits several atoms, the spectrum for single-site addressing is no longer symmetric around the laser frequency. The shape of the spectrum of fluorescent light, therefore, can serve as a test for single-site addressing. The effects we find can be attributed to a dipole-dipole interaction between the atoms due to the mutual exchange of photons.Pioneering methods in recent optical-lattice experiments allow focusing laser beams down to a spot size that is comparable to the lattice constant. Inspired by this achievement, we examine the resonance fluorescence spectra of two-level atoms positioned in adjacent lattice sites and compare the case where the laser hits only one atom (single-site addressing) with cases where several atoms are illuminated. In contrast to the case where the laser hits several atoms, the spectrum for single-site addressing is no longer symmetric around the laser frequency. The shape of the spectrum of fluorescent light, therefore, can serve as a test for single-site addressing. The effects we find can be attributed to a dipole-dipole interaction between the atoms due to the mutual exchange of photons.

arXiv:1111.5494Physical Review AJan 27, 20126 citations

44%

of the sites have a single atom cooled to near its vibrational ground state. A theoretical model of site occupation based on Poisson statistics agrees well with the experimental results.

^{133}\text{C}\text{s}

in a blue-detuned lattice with Raman-transition-based single-qubit gates, given reasonable limits on experimental parameters.