We demonstrate a scalable approach to addressing multiple atomic qubits for use in quantum information processing. Individually trapped 87 Rb atoms in a linear array are selectively manipulated with a single laser guided by a microelectromechanical beam steering system. Single qubit oscillations are shown on multiple sites at frequencies of Ӎ3.5 MHz with negligible crosstalk to neighboring sites. Switching times between the central atom and its closest neighbor were measured to be 6 -7 s while moving between the central atom and an atom two trap sites away took 10-14 s.

Abstract:We present a beam steering system based on microelectromechanical systems technology that features high speed steering of multiple laser beams over a broad wavelength range. By utilizing high speed micromirrors with a broadband metallic coating, our system has the flexibility to simultaneously incorporate a wide range of wavelengths and multiple beams. We demonstrate reconfiguration of two independent beams at different wavelengths (780 and 635 nm) across a common 5×5 array with 4 µs settling time. Full simulation of the optical system provides insights on the scalability of the system. Such a system can provide a versatile tool for applications where fast laser multiplexing is necessary. References and links

p -type InGaAs∕Si heterojunctions were fabricated through a wafer fusion bonding process. The relative band alignment between the two materials at the heterointerface was determined using current-voltage (I-V) measurements and applying thermionic emission-diffusion theory. The valence and conduction band discontinuities for the InGaAs∕Si interface were determined to be 0.48 and −0.1eV, respectively, indicating a type-II band alignment.

In order to provide scalability to quantum information processors utilizing trapped atoms or ions as quantum bits (qubits), the capability to address multiple individual qubits in a largeSome of the most promising physical implementations of quantum information processors (QIPs) utilize internal states of ions coupled via Coulomb interactions [1][2][3][4] or neutral atoms coupled through dipole-dipole interactions [5,6] to represent quantum bits (qubits). Manipulation of qubit states in these QIP implementations require precisely controlled laser beams. While architectures for scalable QIPs have been proposed, [7] their realization is limited by available technology. [8] To improve the scalability of these experiments, an effective means of delivering laser beams to multiple qubit locations is required. Requirements such as fast addressing times (∼ 1µs) imposed by qubit dephasing, [9] broad range of operational wavelengths (UV for trapped ions [2][3][4] and IR for neutral atoms [9,10]), and scalable addressing of thousands of locations exclude the possibility of using traditional optical components. Acousto-optical modulators have been used to provide beam steering to several qubit locations [11], but this approach introduces a frequency shift and is difficult and costly to scale. Optical micro-electromechanical systems (MEMS) can provide a variety of optical 1

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