Modular Entanglement of Atoms

Gallery image 1 Monroe PRA 2014-V1

Modularity is everywhere, from social networks and transportation hubs to biological function. Modular systems are always necessary for mitigating complexity, especially in computer systems where the latest processors have up to 256 modular cores.  We propose a realistic modular quantum computing design that is scalable to huge numbers of qubits, while resistant to errors. Entanglement within a module is afforded through local phonon interactions, which can be extended to other qubit modules through photonic interfaces. Experimentally, we report the first step in such an architecture by entangling remote ions in different ion traps while also showing local entanglement between ions in a single ion trap module as a demonstration of both photon and phonon buses in a single network.  The entanglement rate between modules is nearly 10/sec, orders of magnitude faster than previous results, and much faster than the observed decoherence rate, thus representing the first demonstration of a scalable quantum network in any photonic platform.  Moreover, we show how to phase-lock gates over space and time between multiple modules, a crucial prerequisite for scalability.  We finally show that even if the photons from different modules have different optical frequencies, entanglement fidelity of the linked quantum memories can be recovered, without sacrificing entanglement rate, by feed-forwarding timing information on the coincidence interference.

Ultrafast Spin-Motion Entanglement and Interferometry with a Single Atom

Entanglement in a Flash from JQI News on Vimeo.

The lab’s ultrafa$t team has generated quantum entanglement between a single atom’s motion and its spin state thousands of times faster than previously reported, demonstrating unprecedented control of atomic motion. This work, which may lead to faster and better quantum computer logic gates, is described a recent issue of Physical Review Letters.

This experiment focuses on using highly energetic laser pulses to perform qubit operations. Previously, they set a record for the fastest spin flip in these systems: a mere 50 picoseconds. Here they continue their work by blasting the ion so strongly that the qubit quickly becomes linked to its motion. Such speedy operations are more typically associated with solid state systems such as electrons in semiconductors or superconductors. Here the speed of operations combined with the pristine quantum environment of atoms provide the best of both worlds. READ more @ JQI website

“Ultrafast Spin-Motion Entanglement and Interferometry with a Single Atom,” J. Mizrahi, C. Senko, B. Neyenhuis, K.G. Johnson, W.C. Campbell, C.W.S. Conover, C. Monroe, Physical Review Letters, 103, 203001 (2013).