Chair: (David Allcock (University of Oregon) )
1:30pm - 2:15pmJonathan Home, ETH, Zurich (invited)
Encoded logical qubits and reservoir engineering in a trapped-ion mechanical oscillator
Abstract. I will describe experiments in which measurements of modular functions of position and momentum can be used to encode and manipulate information stored in an oscillator. For trapped-ions, such measurements can be implemented using a single bichromatic coupling between the oscillator and an ancilla spin. This has allowed us to encode and manipulate a logical qubit encoded in grid states of the motional oscillator of a single trapped-ion, which were first proposed by Gottesmann, Kitaev and Preskill. More recently, we have developed a scheme for performing autonomous stabilization of the qubit subspace, replacing the spin measurement with a coherent operation followed by spin relaxation using optical pumping. This scheme represents a form of reservoir engineering, and also results in an efficient form of laser cooling. In addition to work on single oscillators, I will briefly review recent experimental results which target scaling trapped-ion quantum computers into multiple dimensions using arrays of micro-fabricated Penning traps.
2:15pm - 2:45pmAlex Kato, University of Washington
Trapping and manipulating 2D Coulomb crystals for quantum information processing
Abstract. Quantum computation in trapped ions is most commonly performed in linear Paul traps, where excess micromotion can be minimized. 2D coulomb crystals pose several advantages that may enhance the scalability of trapped ion systems and enable more fault tolerant computation schemes. Yet RF ion trap geometries that are capable of trapping 2D crystals inevitably lead to significant micromotion in ions away from the trap center, causing infidelities in qubit operations. Our trap is designed to strongly confine ions to the crystal plane, where transverse micromotion can be minimized and addressing laser beams experience no significant doppler shift. While excess planar micromotion will be present, we seek to demonstrate recently proposed methods that only use transverse modes to apply a spin dependent force to neighbouring ions, while accounting for in-plane micromotion through a series of segmented pulses to achieve high fidelity two qubit operations. We discuss our current progress in trapping and manipulating 2D ion crystals. In addition, we discuss beginning efforts to entangle a single trapped ion to a solid-state zinc oxide defect via direct photonic link.
2:45pm - 3:15pmMaya Berlin-Udi, University of California Berkeley
Exploring electric-field noise mechanisms through treatments of an ion trap surface
Abstract. Electric-field noise is a major limiting factor in the performance and scalability of ion traps. Despite intensive research over the past decade, the microscopic mechanism underlying electric-field noise near surfaces is unknown. We use a single trapped ion as a detector to measure noise at megahertz frequencies, and we find that our measurements are consistent with noise produced by an ensemble of thermally activated fluctuators. We alter the surface with treatments such as prolonged heating and argon ion bombardment, and monitor changes in surface composition and electric field noise in response to these treatments. With these experiments, we establish a concrete link between electric-field noise characteristics and microscopic properties of the ion trap surface.

SQuInT Chief Organizer
Akimasa Miyake, Associate Professor

SQuInT Co-Organizer
Brian Smith, Associate Professor UO

SQuInT Program Committee
Postdoctoral Fellows:
Markus Allgaier (UO OMQ)
Sayonee Ray (UNM CQuIC)
Pablo Poggi (UNM CQuIC)
Valerian Thiel (UO OMQ)

SQuInT Event Co-Organizers (Oregon)
Jorjie Arden
Holly Lynn

SQuInT Event Administrator (Oregon)
Brandy Todd

SQuInT Administrator (CQuIC)
Gloria Cordova
505 277-1850

SQuInT Founder
Ivan Deutsch, Regents' Professor, CQuIC Director

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