Multilayer ion trap technology for scalable quantum computing and quantum simulation

Bautista-Salvador, A.; Zarantonello, Giorgio; Hahn, H.; Preciado-Grijalva, A.; Morgner, Jonathan; Wahnschaffe, M.; Ospelkaus, C.

doi:10.1088/1367-2630/ab0e46

Cited by 23 publications

(20 citation statements)

References 44 publications

(63 reference statements)

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“…The surface-electrode trap was fabricated at the PTB cleanroom facility employing the single-layer method as detailed in ref. 27 on an AlN substrate (for the present trap, we chose the single-layer process in order to quickly test improvements that were made to the setup and trap orientation compared with ref. 28 ).…”

Section: Resultsmentioning

confidence: 99%

Integrated 9Be+ multi-qubit gate device for the ion-trap quantum computer

et al. 2019

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We demonstrate the experimental realization of a two-qubit Mølmer-Sørensen gate on a magnetic field-insensitive hyperfine transition in 9 Be + ions using microwave near-fields emitted by a single microwave conductor embedded in a surface-electrode ion trap. The design of the conductor was optimized to produce a high oscillating magnetic field gradient at the ion position. The measured gate fidelity is determined to be 98.2 ± 1.2% and is limited by technical imperfections, as is confirmed by a comprehensive numerical error analysis. The conductor design can potentially simplify the implementation of multi-qubit gates and represents a self-contained, scalable module for entangling gates within the quantum CCD architecture for an ion-trap quantum computer.

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Section: Resultsmentioning

confidence: 99%

Integrated 9Be+ multi-qubit gate device for the ion-trap quantum computer

et al. 2019

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“…Our group at the Leibniz University of Hannover (LUH) and the Physikalisch-Technische Bundesanstalt (PTB) is focused on developing surface-electrode Paul traps for quantum information processing applications. We have established a simulation and production line for these types of traps and run an experiment at PTB in which these traps are used to drive two-qubit gates [42,43,44,23,45,46]. While the gate fidelities that our group can achieve improved over time [47,48] and the manufacturing capabilities are developed to a point that allows for production of larger scale traps, they still lack operation in a cryogenic environment.…”

Section: Thesis Outlinementioning

confidence: 99%

Ultra-low-vibration closed-cycle cryogenic surface-electrode ion trap apparatus

Dubielzig

Halama

Hahn

et al. 2021

Review of Scientific Instruments

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Trapped ions are one of the leading platforms for building scalable quantum information processors. Current ion traps run on less than 100 qubits. A useful quantum computer needs to operate thousands or even millions of qubits. If systems reach gate fidelities that allow for quantum error correction, gate errors below the physical fidelity can be reached, which is important for scaling. The most promising platform for scaling up ion-based quantum computers are surface electrode traps in connection with the so-called QCCD (Quantum Charge Coupled Device) architecture. In an evolution of the standard (laser-based) approach to quantum logic gates, gates can be performed by applying an oscillating magnetic near-field gradient to the ions. Current fidelities are about one order of magnitude away from reaching the fault tolerant threshold with no fundamental limitations in sight. Scaling QCCDs is impeded by heating rates of the ions as well as vacuum quality. Ions have to be stored for at least as long as it takes for an algorithm to run and subsequent readout. Collisions with background gas and heating can expel ions from the trap. The microwave near-field approach of driving gates benefits from ions that are trapped close to the trap surface. Unfortunately, heating becomes more prominent near the surface. A cryogenic environment reduces the background pressure by several orders of magnitude and the kinetic energy of gas molecules by two orders of magnitude. Heating rates in a cryogenic trap are about two orders of magnitude lower than in a room temperature trap with otherwise equal physical properties. To operate a QCCD processor, it is required to employ phase-stable Raman laser beams. The cryogenic design of the apparatus needs to take into account the resulting requirements for ultra-low vibration amplitudes. This is particularly relevant for closed-cycle cooling systems, which are desirable from an economic point of view compared to liquid cryostats that boil off helium, but which also feature moving mechanical parts that can introduce a serious amount of vibrations. Here, we present a vibration isolated closed cycle Gifford-McMahon cryocooler with record low vibration amplitudes of 29 nm (RMS=7.8 nm) in the vertical and 51 nm (RMS=13.5 nm) in the horizontal direction. It contains a self-sustained inner vacuum chamber that houses the trap. It features 100 DC connections, 10 of which are able to carry up to 1 A of current and 8 high frequency lines. At 5 K, we can apply continuous 3.4 W of microwave power continuously at 1 GHz to the trap electrodes without heating the system. This is about 5.8 times more than state of the art near-field gates require. We also present the laser systems required to for single-shot ablation loading and Doppler cooling of 9 Be + ions: a 70 mW 313 nm Dopper cooling laser, a 1064 nm ns-pulse laser for ablation of neutral beryllium atoms and a 235 nm laser for ionizing them. The detection system features an in vacuum imaging system on a cryogenic 3D translation stage that is able to scan...

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“…Ref. [103] demonstrated a polymer-based, spin-on dielectric for ion trap fabrication, which allowed for thick dielectric layers. The deposition of the top metal layer (M2) can be performed by using conventional microfabrication processes including electroplating, sputtering, evaporation (Fig.…”

Section: Standard Fabrication Processes For Ion Trapsmentioning

confidence: 99%