A review of silicon microfabricated ion traps for quantum information processing
 DongIl “Dan” Cho^{1}Email author,
 Seokjun Hong^{1},
 Minjae Lee^{1} and
 Taehyun Kim^{2}
DOI: 10.1186/s4048601500133
© Cho et al.; licensee Springer. 2015
Received: 12 December 2014
Accepted: 13 January 2015
Published: 23 April 2015
Abstract
Quantum information processing (QIP) has become a hot research topic as evidenced by S. Haroche and D. J. Wineland receiving the Nobel Prize in Physics in 2012. Various MEMSbased microfabrication methods will be a key enabling technology in implementing novel and scalable ion traps for QIP. This paper provides a brief introduction of ion trap devices, and reviews ion traps made using conventional precision machining as well as MEMSbased microfabrication. Then, microfabrication methods for ion traps are explained in detail. Finally, current research issues in microfabricated ion traps are presented. The QIP renders significant new challenges for MEMS, as various QIP technologies are being developed for secure encrypted communication and complex computing applications.
Keywords
Microelectromechanial System (MEMS) Microfabrication Ion traps Quantum information processing (QIP) Quantum computingIntroduction
Quantum information processing (QIP) is a novel information processing method based on quantum mechanics [13], and uses two quantum states in a quantum system as a basic unit of information, instead of two voltage levels in conventional information processing based on electronics. This basic unit is called “qubit”, an abbreviation for quantum bit. The information stored in a single qubit exists in a superposition of two quantum states which indicates an arbitrary linear combination of two orthonormal basis. Since a single qubit can occupy either of two states simultaneously, N qubits can represent 2^{N} states of information. Moreover, using a quantum teleportation process [4], two qubits can provide the same measurement results, regardless of the distance between the qubits. Based on these phenomena in the quantum regime, QIP is expected to achieve noticeable increases in the speed in information processing problems. Therefore, many QIP applications such as quantum communication [57], quantum computer [812], and quantum simulator [1315] have been proposed and are being actively researched.
For the physical implementation of the qubit, a quantum system which is sufficiently isolated from their surroundings and can be individually manipulated is required. Individual manipulation means qubits are initializable, controllable and measureable. A single atomic ion confined by a physical platform which is called “ion trap” satisfies the requirements [1619]. Thus the ion trap has become one of the leading technologies among the various qubit platforms including superconducting circuit [2022], optical lattice [23,24], nuclear magnetic resonance (NMR) [25,26], and quantum dot [27,28]. The ion trap was initially developed by Wolfgang Paul and Hans Georg Dehmelt who are the cowinners of the Nobel Prize in Physics in 1989. Since Cirac and Zoller have proposed using trapped ions as a physical implementation of qubit [16], the feasibility of ion qubits has been verified through many experiments [19,29,30]. Recently, in 2012, Serge Haroche and David Wineland received the Nobel Prize in Physics owing to the measurement and manipulation of individual quantum systems, using cavity quantum electrodynamics (QED) and ion traps, respectively. There has been several review articles on the subject of quantum information processing [18,3134].
Although the earlier Paul traps were constructed by conventional precision machining method and careful manual assembling, with the advances in MEMS, recent ion traps are based on silicon microfabrication technologies. The basic principles of ion traps are presented in Types of ion trap section. Then, Development history of Paul trap section discusses a history of the Paul trap, which is the type of ion traps mainly covered in this paper. In MEMSbased microfabrication section, two MEMS microfabrication methods for ion traps are explained. Finally, the current issues and the future development directions of microfabricated ion traps are presented in Future directions section.
Types of ion trap
An ion trap is a device which can trap charged particles in space by using electric or electromagnetic fields. Trapping a charged particle with static potential alone is impossible because the static potential (φ) obeys one of Maxwell’s equations ∇^{2} φ = 0 [35]. Wolfgang Paul used an oscillating electric field together with the static electric field [36], and Hans Georg Dehmelt added a magnetic field to the static electric field to trap a positive ion [37]. The ion traps built by Paul and Dehmelt are called “Paul trap” and “Penning trap”^{a} [38] respectively. In this paper, we cover only the Paul trap, because the Paul trap is currently widely used for QIP applications.
Development history of Paul trap
Ring trap
In the early stages of ion trap researches, the ring type Paul trap was used for experiments concerned in fundamental physics such as frequency standards [41] and mass spectroscopy [42,43]. Ring traps can be easily constructed because of its simple structure, but has a drawback in trapping large numbers of ions because a potential minimum exists at a specific point and difficult to be expanded to a 3D space.
Linear trap
Cirac and Zoller [16] proposed using trapped ions as a physical implementation of quantum computation. Since then, many research groups have been using linear traps in their QIP experiments. Most of the groups have developed their own linear traps using precision machining and assembling techniques. Each research group has a different electrode structure. Some typical electrode structures include rods [45,47], blades [48,49] and sheets [50]. Figure 2(b) shows a blade type linear trap of the Innsbruck group [48]. Many ion trap research groups are still using a variation of these 4rod linear traps. In general, when compared to the surface traps (explained in the following subsection) the 4rod linear traps have a higher trap depth, which in turn provide a longer ion life time and more stable trapping of ions. However, the linear traps do not offer the design freedom of the surface traps, and currently more research efforts are being expended to the surface traps.
Surface trap
To implement more complicated quantum operations, more ions that can be manipulated in a common motional mode (which refers to the collective oscillation of the whole ion string) should be trapped. Therefore the idea of integrating multiple ion trap arrays in a single ion trap chip was proposed [12,51]. The ion trap chip integrated with multiple ion trap arrays is divided into different regions, as an operation region in which the quantum operations are held, a memory region that stores ions conserving qubit states, and a region for loading ions.
In addition to the Sibased surface traps mentioned in the above, surface traps with a single metal layer on a nonconductive substrate, fabricated by patterning Au electrodes on quartz or sapphire substrates [54,6669] have been reported. A surface trap has also been fabricated on printed circuit boards [7072].
MEMSbased microfabrication
Although many results have been reported on trapping ions with MEMSfabricated traps, the process details to fabricate the trap chips are very scarce in the literature. Fabricating ion traps requires thick dielectric films to withstand several hundred volts of RF voltages. However, the dielectric layer should be as invisible as possible as seen from the RF null point where ions are trapped, since dielectric charging phenomena can alter the null position and can induce the micromotion of trapped ions. In this section, we introduce two fabrication methods developed by us.
Future directions
Junction ion trap
As discussed in Development history of Paul trap, the number of ion qubits trapped in an ion trap array inevitably must increase in order to adapt more complex quantum algorithms [12]. For trapping and manipulating large numbers of ions, a multizone ion trap composed by a number of ion trap arrays is proposed. In this multizone ion trap, the trapping zones are connected by “X” or “Y” junctions, and the information stored in ions can be transferred from one zone to another through the junctions. For shuttling the ions in an axial direction, the location of DC null point is moved along the axial direction by applying timedependent potentials to the outer DC control electrodes. Ion transports via junctions however require not only applying DC control voltages, but more complex techniques, because pseudopotential barriers created by RF voltages exist near the center of the junctions. Therefore, the geometries near the junctions should be optimized by an iterative algorithm to minimize the magnitude of the pseudopotential barriers.
3D ion trap fabricated by microfabrication technology
Conclusion
This paper reviewed the operation principles and the development history of ion traps. Ion trap has a huge potential to be used in quantum information processing and computing. By applying MEMSbased microfabrication methods as well as conventional machining techniques, various ion traps for QIP experiments have been built and demonstrated. This paper also showed two variations of MEMS fabrication method for surface ion traps. It is expected that the ion trap technology can contribute to realize novel quantum information processing methods with exponential speedup that we have never experienced so far. It is also expected and anticipated that MEMS fabrication technologies will be crucially instrumental in realizing complex yet inexpensive ion traps for quantum information processing and computing.
Endnote
^{a}Penning trap: The Penning Trap was named after F. M. Penning by Hans Georg Dehmelt because Dehmelt stated getting the inspiration of the trap from the vacuum gauge built by F. M. Penning [38].
Abbreviations
 AlGaAs:

Aluminum gallium arsenide
 NIST:

National Institute of Standards and Technology
 BHF:

Buffered hydrogen fluoride
 NMR:

Nuclear magnetic resonance
 BOE:

Buffered oxide etching
 NPL:

National Physical Laboratory
 CCD:

Charge coupled device
 PECVD:

Plasma enhanced chemical vapor deposition
 CMP:

Chemical mechanical polishing
 PR:

Photoresist
 DRIE:

Deep reactive ion etching
 QED:

Quantum electrodynamics
 EMCCD:

Electron multiplying charge coupled device
 QIP:

Quantum information processing
 GaAs:

Gallium arsenide
 SEM:

Scanning electron micrograph
 LPCVD:

Low pressure chemical vapor deposition
 SNL:

Sandia National Laboratory
 MEMS:

Microelectromechanical system
 TSV:

Through silicon via
Declarations
Acknowledgements
Taehyun Kim was supported by ICT R&D program of MSIP/IITP. [10043464, Development of quantum repeater technology for the application to communication systems].
Authors’ Affiliations
References
 Wiesner S (1983) Conjugate coding. ACM Sigact News 15(1):78–88View ArticleGoogle Scholar
 Schumacher B (1995) Quantum coding. Physical Review A 51(4):2738View ArticleMathSciNetGoogle Scholar
 Nielsen MA, Chuang IL (2010) Quantum computation and quantum information. Cambridge, UK: Cambridge university press
 Bennett CH, Brassard G, Crépeau C, Jozsa R, Peres A, Wootters WK (1993) Teleporting an unknown quantum state via dual classical and EinsteinPodolskyRosen channels. Physical Review Letters 70(13):1895View ArticleMATHMathSciNetGoogle Scholar
 Bennett CH, Brassard G (1984) Quantum cryptography: Public key distribution and coin tossing. In Proceedings of IEEE International Conference on Computers, Systems and. Signal Processing 175(150):8Google Scholar
 Briegel HJ, Dür W, Cirac JI, Zoller P (1998) Quantum repeaters: The role of imperfect local operations in quantum communication. Physical Review Letters 81(26):5932View ArticleGoogle Scholar
 Duan LM, Lukin MD, Cirac JI, Zoller P (2001) Longdistance quantum communication with atomic ensembles and linear optics. Nature 414(6862):413–418View ArticleGoogle Scholar
 Deutsch D, Jozsa R (1992) Rapid solution of problems by quantum computation. In proceedings of the Royal Society of London Series A: Mathematical and Physical Sciences 439(1907):553–558View ArticleMATHMathSciNetGoogle Scholar
 Shor PW (1994) Algorithms for quantum computation: Discrete logarithms and factoring. In proceedings of 35th Annual Symposium on Foundations of Computer Science: 124–134
 DiVincenzo DP (1995) Quantum computation. Science 270(5234):255–261View ArticleMATHMathSciNetGoogle Scholar
 Jones JA, Mosca M, Hansen RH (1998) Implementation of a quantum search algorithm on a quantum computer. Nature 393(6683):344–346View ArticleGoogle Scholar
 Kielpinski D, Monroe C, Wineland DJ (2002) Architecture for a largescale iontrap quantum computer. Nature 417(6890):709–711View ArticleGoogle Scholar
 Feynman RP (1982) Simulating physics with computers. International journal of theoretical physics 21(6):467–488View ArticleMathSciNetGoogle Scholar
 AspuruGuzik A, Dutoi AD, Love PJ, HeadGordon M (2005) Simulated quantum computation of molecular energies. Science 309(5741):1704–1707View ArticleGoogle Scholar
 Buluta I, Nori F (2009) Quantum simulators. Science 326(5949):108–111View ArticleGoogle Scholar
 Cirac JI, Zoller P (1995) Quantum computations with cold trapped ions. Physical review letters 74(20):4091–4094View ArticleGoogle Scholar
 SchmidtKaler F, Häffner H, Riebe M, Gulde S, Lancaster GP, Deuschle T, Becher C, Roos CF, Eschner J, Blatt R (2003) Realization of the Cirac–Zoller controlledNOT quantum gate. Nature 422(6930):408–411View ArticleGoogle Scholar
 Blatt R, Wineland D (2008) Entangled states of trapped atomic ions. Nature 453(7198):1008–1015View ArticleGoogle Scholar
 Home JP, Hanneke D, Jost JD, Amini JM, Leibfried D, Wineland DJ (2009) Complete methods set for scalable ion trap quantum information processing. Science 325(5945):1227–1230View ArticleMATHMathSciNetGoogle Scholar
 Devoret MH, Schoelkopf RJ (2013) Superconducting circuits for quantum information: an outlook. Science 339(6124):1169–1174View ArticleMathSciNetGoogle Scholar
 Martinis JM, Nam S, Aumentado J, Urbina C (2002) Rabi oscillations in a large Josephsonjunction qubit. Physical Review Letters 89(11):117901View ArticleGoogle Scholar
 Clarke J, Wilhelm FK (2008) Superconducting quantum bits. Nature 453(7198):1031–1042View ArticleGoogle Scholar
 Pachos JK, Knight PL (2003) Quantum computation with a onedimensional optical lattice. Physical review letters 91(10):107902View ArticleGoogle Scholar
 Brennen GK, Caves CM, Jessen PS, Deutsch IH (1999) Quantum logic gates in optical lattices. Physical Review Letters 82(5):1060View ArticleGoogle Scholar
 Gershenfeld NA, Chuang IL (1997) Bulk spinresonance quantum computation. science, 275(5298): 350–356
 Vandersypen LM, Chuang IL (2005) NMR techniques for quantum control and computation. Reviews of modern physics 76(4):1037View ArticleGoogle Scholar
 Imamog A, Awschalom DD, Burkard G, DiVincenzo DP, Loss D, Sherwin M, Small A (1999) Quantum information processing using quantum dot spins and cavity QED. Physical Review Letters 83(20):4204View ArticleGoogle Scholar
 Loss D, DiVincenzo DP (1998) Quantum computation with quantum dots. Physical Review A 57(1):120View ArticleGoogle Scholar
 Moehring DL, Maunz P, Olmschenk S, Younge KC, Matsukevich DN, Duan LM, Monroe C (2007) Entanglement of singleatom quantum bits at a distance. Nature 449(7158):68–71View ArticleGoogle Scholar
 Leibfried D, DeMarco B, Meyer V, Lucas D, Barrett M, Britton J, Itano WM, Jelenkovic B, Langer C, Rosenband T, Wineland DJ (2003) Experimental demonstration of a robust, highfidelity geometric two ionqubit phase gate. Nature 422(6930):412–415View ArticleGoogle Scholar
 Steane A (1997) The ion trap quantum information processor. Applied Physics B: Lasers and Optics 64(6):623–643View ArticleGoogle Scholar
 Monroe C, Kim J (2013) Scaling the ion trap quantum processor. Science 339(6124):1164–1169View ArticleGoogle Scholar
 Kimble H (2008) The quantum internet. Nature 453(7198):1023–1030View ArticleGoogle Scholar
 Ladd TD, Jelezko F, Laflamme R, Nakamura Y, Monroe C, O’Brien JL (2010) Quantum computers. Nature 464(7285):45–53View ArticleGoogle Scholar
 Griffiths DJ, Reed College (1999) Introduction to electrodynamics (Vol. 3). Upper Saddle River, NJ: prentice Hall
 Paul W, Reinhard HP, Zahn U (1959) Das elektrische Massenfilter als Massenspektrometer und Isotopentrenner. Zeitschrift für Physik 152(2):143–182View ArticleGoogle Scholar
 Dehmelt HG (1967) Radiofrequency spectroscopy of stored ions I: Storage. Adv At Mol Phys 3:53View ArticleGoogle Scholar
 Penning FM, Nienhuis K (1949) Construction and applications of a new design of the Philips vacuum gauge. Philips Technical Review, Netherlands, p 11Google Scholar
 Webpage of Department of Physics and Astronomy at Bonn University in 2014 [http://bigs.physicsastro.unibonn.de/index.php?id=76]
 March RE (2009) Quadrupole ion traps. Mass spectrometry reviews 28(6):961–989View ArticleGoogle Scholar
 Wineland DJ, Bergquist JC, Bollinger JJ, Itano WM, Heinzen DJ, Gilbert SL, Manney CH, Raizen MG (1990) Progress at NIST toward absolute frequency standards using stored ions. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on 37(6):515–523View ArticleGoogle Scholar
 Louris JN, Cooks RG, Syka J, Kelley PE, Stafford GC, Todd JF (1987) Instrumentation, applications, and energy deposition in quadrupole iontrap tandem mass spectrometry. Analytical Chemistry 59(13):1677–1685View ArticleGoogle Scholar
 Kaiser RE, Graham CR, Stafford GC, Syka JE, Hemberger P (1991) Operation of a quadrupole ion trap mass spectrometer to achieve high mass/charge ratios. International journal of mass spectrometry and ion processes 106:79–115View ArticleGoogle Scholar
 Prestage JD, Dick GJ, Maleki L (1989) New ion trap for frequency standard applications. Journal of Applied Physics 66(3):1013–1017View ArticleGoogle Scholar
 Raizen MG, Gilligan JM, Bergquist JC, Itano WM, Wineland DJ (1992) Ionic crystals in a linear Paul trap. Physical Review A 45(9):6493View ArticleGoogle Scholar
 Monz T, Schindler P, Barreiro JT, Chwalla M, Nigg D, Coish WA, Harlander M, Hänsel W, Hennrich M, Blatt R (2011) 14qubit entanglement: Creation and coherence. Physical Review Letters 106(13):130506
 Nägerl HC (1998) Ion strings for quantum computation. Ph.D dissertation
 Webpage of Institut für Quantenoptik und Quanteninformation at Innsbruck [http://heartc704.uibk.ac.at/index.php/en/research/lintrap]
 Huber G, Deuschle T, Schnitzler W, Reichle R, Singer K, SchmidtKaler F (2008) Transport of ions in a segmented linear Paul trap in printedcircuitboard technology. New Journal of Physics 10(1): 013004
 Brama E, Mortensen A, Keller M, Lange W (2012) Heating rates in a thin ion trap for microcavity experiments. Applied Physics B 107(4):945–954View ArticleGoogle Scholar
 Cirac JI, Zoller P (2000) A scalable quantum computer with ions in an array of microtraps. Nature 404(6778):579–581View ArticleGoogle Scholar
 Madsen MJ, Hensinger WK, Stick D, Rabchuk JA, Monroe C (2004) Planar ion trap geometry for microfabrication. Applied Physics B 78(5):639–651View ArticleGoogle Scholar
 Stick D, Hensinger WK, Olmschenk S, Madsen MJ, Schwab K, Monroe C (2005) Ion trap in a semiconductor chip. Nature Physics 2(1):36–39View ArticleGoogle Scholar
 Seidelin S, Chiaverini J, Reichle R, Bollinger JJ, Leibfried D, Britton J, Wesenberg JH, Blakestad RB, Epstein RJ, Hume DB, Jost JD, Langer C, Ozeri R, Shiga N, Wineland DJ (2006) Microfabricated surfaceelectrode ion trap for scalable quantum information processing. Physical review letters 96(25):253003View ArticleGoogle Scholar
 Wesenberg JH (2008) Electrostatics of surfaceelectrode ion traps. Physical Review A 78(6):063410View ArticleGoogle Scholar
 Reichel J, Vuletic V (2010) Atom chips, Hoboken, NJ: John Wiley & SonsGoogle Scholar
 Hughes MD, Lekitsch B, Broersma JA, Hensinger WK (2011) Microfabricated ion traps. Contemporary Physics 52(6):505–529View ArticleGoogle Scholar
 Stajic J (2013) The future of quantum information processing. Science 339(6124):1163–1163View ArticleGoogle Scholar
 Stick D, Fortier KM, Haltli R, Highstrete C, Moehring DL, Tigges C, Blain MG (2010) Demonstration of a microfabricated surface electrode ion trap. arXiv preprint arXiv:1008.0990
 Leibrandt DR, Labaziewicz J, Clark RF, Chuang IL, Epstein RJ, Ospelkaus C, Wesenberg JH, Bollinger JJ, Leibfried D, Wineland DJ, Stick D, Sterk J, Monroe C, Pai CS, Low Y, Frahm R, Slusher RE (2009) Demonstration of a scalable, multiplexed ion trap for quantum information processing. Quantum Information & Computation 9(11):901–919Google Scholar
 Merrill JT, Volin C, Landgren D, Amini JM, Wright K, Doret SC, Pai CS, Hayden H, Killian T, Faircloth D, Brown KR, Harter AW, Slusher RE (2011) Demonstration of integrated microscale optics in surfaceelectrode ion traps. New Journal of Physics 13(10):103005View ArticleGoogle Scholar
 Kim T, Yoon J, Ahn J, Kim M, Kim J, Choi D, Hong S, Lee M, and Cho, D (2013) Development of quantum repeater based on ion trap. The 4th International Quantum Optics Workshop
 Ramm M, Pruttivarasin T, Häffner H (2013) Energy Transport in Trapped Ion Chains. arXiv preprint arXiv:1312.5786
 Mount E, Baek SY, Blain M, Stick D, Gaultney D, Crain S, Noek R, Kim T, Maunz P, Kim J (2013) Single qubit manipulation in a microfabricated surface electrode ion trap. New Journal of Physics 15(9):093018View ArticleGoogle Scholar
 Shu G, Vittorini G, Buikema A, Nichols CS, Volin C, Stick D, Brown KR (2014) Heating rates and ionmotion control in a Yjunction surfaceelectrode trap. Physical Review A 89(6):062308View ArticleGoogle Scholar
 Allcock DTC, Sherman JA, Stacey DN, Burrell AH, Curtis MJ, Imreh G, Linke NM, Szwer DJ, Webster SC, Steane AM, Lucas DM (2010) Implementation of a symmetric surfaceelectrode ion trap with field compensation using a modulated Raman effect. New Journal of Physics 12(5):053026View ArticleGoogle Scholar
 Amini JM, Uys H, Wesenberg JH, Seidelin S, Britton J, Bollinger JJ, Leibfried D, Ospelkaus C, VanDevender AP, Wineland DJ (2010) Toward scalable ion traps for quantum information processing. New journal of Physics 12(3):033031View ArticleGoogle Scholar
 Tanaka U, Suzuki K, Ibaraki Y, Urabe S (2014) Design of a surface electrode trap for parallel ion strings. Journal of Physics B: Atomic, Molecular and Optical Physics, 47(3):035301
 Noek R, Kim T, Mount E, Baek SY, Maunz P, Kim J (2013) Trapping and cooling of 174Yb + ions in a microfabricated surface trap. Journal of the Korean Physical Society 63(4):907–913View ArticleGoogle Scholar
 Brown KR, Clark RJ, Labaziewicz J, Richerme P, Leibrandt DR, Chuang IL (2007) Loading and characterization of a printedcircuitboard atomic ion trap. Physical Review A 75(1):015401View ArticleGoogle Scholar
 Li X, Jiang G, Luo C, Xu F, Wang Y, Ding L, Ding CF (2009) Ion trap array mass analyzer: structure and performance. Analytical chemistry 81(12):4840–4846View ArticleGoogle Scholar
 Kim TH, Herskind PF, Kim T, Kim J, Chuang IL (2010) Surfaceelectrode point Paul trap. Physical Review A 82(4):043412View ArticleGoogle Scholar
 Hensinger WK, Olmschenk S, Stick D, Hucul D, Yeo M, Acton M, Deslauriers L, Monroe C, Rabchuk J (2006) Tjunction ion trap array for twodimensional ion shuttling, storage, and manipulation. Appl Phys Lett 88(3):034101View ArticleGoogle Scholar
 Blakestad RB, Ospelkaus C, VanDevender AP, Amini JM, Britton J, Leibfried D, Wineland DJ (2009) HighFidelity Transport of TrappedIon Qubits through an XJunction Trap Array. Phys Rev Lett 102(15):153002View ArticleGoogle Scholar
 Blakestad RB, Ospelkaus C, VanDevender AP, Wesenberg JH, Biercuk MJ, Leibfried D, Wineland DJ (2011) Neargroundstate transport of trappedion qubits through a multidimensional array. Physical Review A 84(3):032314View ArticleGoogle Scholar
 Moehring DL, Highstrete C, Stick D, Fortier KM, Haltli R, Tigges C, Blain MG (2011) Design, fabrication and experimental demonstration of junction surface ion traps. New Journal of Physics 13(7):075018View ArticleGoogle Scholar
 Wright K, Amini JM, Faircloth DL, Volin C, Doret SC, Hayden H, Pai CS, Landgren DW, Denison D, Killian T, Slusher RE, Harter AW (2013) Reliable transport through a microfabricated Xjunction surfaceelectrode ion trap. New Journal of Physics 15(3):033004View ArticleGoogle Scholar
 Brownnutt M, Wilpers G, Gill P, Thompson RC, Sinclair AG (2006) Monolithic microfabricated ion trap chip design for scaleable quantum processors. New Journal of Physics 8(10):232View ArticleGoogle Scholar
 Wilpers G, See P, Gill P, Sinclair AG (2012) A monolithic array of threedimensional ion traps fabricated with conventional semiconductor technology. Nature nanotechnology 7(9):572–576View ArticleGoogle Scholar
 See P, Wilpers G, Gill P, Sinclair AG (2013) Fabrication of a Monolithic Array of Three Dimensional Sibased Ion Traps. Journal of Microelectromechanical System 22(5):1180–1189View ArticleGoogle Scholar
 Shaikh F, Ozakin A, Amini JM, Hayden H, Pai CS, Volin C, Denison DR, Faircloth D, Harter AW, Slusher RE (2011) Monolithic Microfabricated Symmetric Ion Trap for Quantum Information Processing. arXiv preprint arXiv:1105.4909
Copyright
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.