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Merkel B, Thirumalai K, Tarlton JE, Schäfer VM, Ballance CJ, Harty TP, Lucas DM. Magnetic field stabilization system for atomic physics experiments. Rev Sci Instrum 2019; 90:044702. [PMID: 31042982 DOI: 10.1063/1.5080093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
Atomic physics experiments commonly use millitesla-scale magnetic fields to provide a quantization axis. As atomic transition frequencies depend on the magnitude of this field, many experiments require a stable absolute field. Most setups use electromagnets, which require a power supply stability not usually met by commercially available units. We demonstrate the stabilization of a field of 14.6 mT to 4.3 nT rms noise (0.29 ppm), compared to noise of >100 nT without any stabilization. The rms noise is measured using a field-dependent hyperfine transition in a single 43Ca+ ion held in a Paul trap at the center of the magnetic field coils. For the 43Ca+ "atomic clock" qubit transition at 14.6 mT, which depends on the field only in second order, this would yield a projected coherence time of many hours. Our system consists of a feedback loop and a feedforward circuit that control the current through the field coils and could easily be adapted to other field amplitudes, making it suitable for other applications such as neutral atom traps.
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Affiliation(s)
- B Merkel
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - K Thirumalai
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - J E Tarlton
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - V M Schäfer
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - C J Ballance
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - T P Harty
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D M Lucas
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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Kurzmann A, Merkel B, Labud PA, Ludwig A, Wieck AD, Lorke A, Geller M. Optical Blocking of Electron Tunneling into a Single Self-Assembled Quantum Dot. Phys Rev Lett 2016; 117:017401. [PMID: 27419589 DOI: 10.1103/physrevlett.117.017401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Indexed: 06/06/2023]
Abstract
Time-resolved resonance fluorescence (RF) is used to analyze electron tunneling between a single self-assembled quantum dot (QD) and an electron reservoir. In equilibrium, the RF intensity reflects the average electron occupation of the QD and exhibits a gate voltage dependence that is given by the Fermi distribution in the reservoir. In the time-resolved signal, however, we find that the relaxation rate for electron tunneling is, surprisingly, independent of the occupation in the charge reservoir-in contrast to results from all-electrical transport measurements. Using a master equation approach, which includes both the electron tunneling and the optical excitation or recombination, we are able to explain the experimental data by optical blocking, which also reduces the electron tunneling rate when the QD is occupied by an exciton.
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Affiliation(s)
- A Kurzmann
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
| | - B Merkel
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
| | - P A Labud
- Chair of Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - A Ludwig
- Chair of Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - A D Wieck
- Chair of Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - A Lorke
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
| | - M Geller
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
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Merkel B, Reichling J. Comparative Investigation on Formation and Accumulation of Rare Phenylpropanoids in Plants and in vitro Cultures of Pimpinella major. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/znc-1990-0607] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Unorganized callus and leaf/root-differentiating callus cultures of Pimpinella major have been established in liquid nutrient medium. Their capacity to accumulate rare phenylpropanoids such as epoxy-pseudoisoeugenol tiglate, epoxy-anol tiglate and anol tiglate was compared with that of seedlings and whole plants. The unorganized callus cultures were not able to accumulate any phenylpropanoids. In comparison, the leaf/root-differentiating callus culture promoted the accumulation of epoxy-pseudoisoeugenol tiglate (up to 90 mg/100 g fr.wt.) but not that of anol-derivatives. The accumulated amount of EPT in PMD-SH was comparable with that in plant seedlings.
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Affiliation(s)
- B. Merkel
- Institut für Pharmazeutische Biologie der Universität Heidelberg, Im Neuenheimer Feld 364, 6900 Heidelberg 1, Bundesrepublik Deutschland
| | - J. Reichling
- Institut für Pharmazeutische Biologie der Universität Heidelberg, Im Neuenheimer Feld 364, 6900 Heidelberg 1, Bundesrepublik Deutschland
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Gabrielsen TM, Merkel B, Søreide JE, Johansson-Karlsson E, Bailey A, Vogedes D, Nygård H, Varpe Ø, Berge J. Potential misidentifications of two climate indicator species of the marine arctic ecosystem: Calanus glacialis and C. finmarchicus. Polar Biol 2012. [DOI: 10.1007/s00300-012-1202-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Althaus M, Wenzel MT, Merkel B, Peitgen HO. Eine dedizierte Benutzeroberfläche zur Auswertung von in vivo MR spektroskopischen Bildgebungsdaten. ROFO-FORTSCHR RONTG 2007. [DOI: 10.1055/s-2007-977223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Akerib DS, Alvaro-Dean J, Armel-Funkhouser MS, Attisha MJ, Baudis L, Bauer DA, Beaty J, Brink PL, Bunker R, Burke SP, Cabrera B, Caldwell DO, Callahan D, Castle JP, Chang CL, Choate R, Crisler MB, Cushman P, Dixon R, Dragowsky MR, Driscoll DD, Duong L, Emes J, Ferril R, Filippini J, Gaitskell RJ, Haldeman M, Hale D, Holmgren D, Huber ME, Johnson B, Johnson W, Kamat S, Kozlovsky M, Kula L, Kyre S, Lambin B, Lu A, Mahapatra R, Manalaysay AG, Mandic V, May J, McDonald R, Merkel B, Meunier P, Mirabolfathi N, Morrison S, Nelson H, Nelson R, Novak L, Ogburn RW, Orr S, Perera TA, Perillo Isaac MC, Ramberg E, Rau W, Reisetter A, Ross RR, Saab T, Sadoulet B, Sander J, Savage C, Schmitt RL, Schnee RW, Seitz DN, Serfass B, Smith A, Smith G, Spadafora AL, Sundqvist K, Thompson JPF, Tomada A, Wang G, Williams J, Yellin S, Young BA. First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory. Phys Rev Lett 2004; 93:211301. [PMID: 15600991 DOI: 10.1103/physrevlett.93.211301] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Indexed: 05/24/2023]
Abstract
We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.
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Affiliation(s)
- D S Akerib
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Abstract
Removal of uranium(VI) by zerovalent iron has been suggested as a feasible pathway to control uranium contaminations in seepage waters. Available information in the literature however presents discrepant evidence on the process responsible for the mitigation effect. On basis of an EH-pH diagram of uranium and iron, it is outlined that these discrepancies may be explained by the aqueous chemistry of uranium and iron. Additional effects contributing to the complexity of the system are given. Solubilization experiments using scrap iron together with water works sludge, MnO2, and pyrite indicate that U(VI) is immobilized by iron corrosion products after about 50 days.
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Affiliation(s)
- C Noubactep
- Centre of Geosciences-Applied Geology, Goldschmidtstrasse 3, D-37077 Göttingen, Germany.
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Volke P, Merkel B. Anwendung eines neuen Feldanalysenverfahrens zur Untersuchung der Stabilität von Arsen und seinen anorganischen Spezies in aquatischen Systemen. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1521-401x(199907)27:4<230::aid-aheh230>3.0.co;2-e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Riechling J, Merkel B. Elicitor-Induced Formation of Coumarin Derivatives in Suspension Cultures of Pimpinella anisum. Planta Med 1993; 59:187-8. [PMID: 17230357 DOI: 10.1055/s-2006-959644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Affiliation(s)
- J Riechling
- Institut für Pharmazeutische Biologie der Universität Heidelberg, Im Neuenheimer Feld 364, D(W)-6900 Heidelberg 1, Federal Republic of Germany
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Appel JA, Bagnaia P, Banner M, Battiston R, Bernlöhr K, Borer K, Borghini M, Bürger J, Carboni G, Cavasinni V, Cenci P, Chollet JC, Clark AG, Codino A, Conta C, Darriulat P, Lotto B, Prete T, Lella L, Dines-Hansen J, Einsweiler K, Engelmann R, Fayard L, Fraternali M, Froidevaux D, Gaillard JM, Gildemeister O, Goggi VG, Gössling C, Hahn B, Hänni H, Hansen JR, Hansen P, Harnew N, Himel T, Iconomidou-Fayard L, Jakobs K, Jenni P, Kluge EE, Kofoed-Hansen O, Lançon E, Livan M, Loucatos S, Madsen B, Mani P, Mansoulié B, Mantovani GC, Mapelli L, Meier K, Merkel B, Mollerud R, Moniez M, Moning R, Morganti M, Onions C, Parker MA, Parrour G, Pastore F, Pepe M, Plothow-Besch H, Polverel M, Repellin JP, Rimoldi A, Rothenberg AF, Roussarie A, Ruhlmann V, Sauvage G, Schacher J, Schlötelburg M, Stocker F, Swartz M, Teiger J, Tovey SN, Tsang WY, Valdata-Nappi M, Vercesi V, Weidberg AR, Wunsch M, Zaccone H. A study of three-jet events at the CERN $$\bar pp$$ collider. ACTA ACUST UNITED AC 1986. [DOI: 10.1007/bf01557598] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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