Emergence of Quantum Phase-Slip Behaviour in Superconducting NbN Nanowires: DC Electrical Transport and Fabrication Technologies
<p>Measurements and analysis of <math display="inline"> <semantics> <mrow> <mi>R</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </semantics> </math> for NbN films with thickness <span class="html-italic">d</span> in the range 10–103 nm. (<b>a</b>) Sheet resistance <math display="inline"> <semantics> <mrow> <msub> <mi>R</mi> <mo>□</mo> </msub> <mrow> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </mrow> </semantics> </math>. The films with thickness of 10 nm and 26 nm were patterned into structures with 90-μm-wide, 2.4-mm-long tracks prior to measurement; the other measurements were carried out on unpatterned films. (<b>b</b>) The same data as (a) at low <span class="html-italic">T</span>, normalised to the maximum resistance <math display="inline"> <semantics> <msub> <mi>R</mi> <mi>max</mi> </msub> </semantics> </math>. (<b>c</b>) Variation of <math display="inline"> <semantics> <msub> <mi>T</mi> <mi mathvariant="normal">c</mi> </msub> </semantics> </math> with low-temperature maximum <math display="inline"> <semantics> <msub> <mi>R</mi> <mo>□</mo> </msub> </semantics> </math>. The line shows a fit to <math display="inline"> <semantics> <mrow> <msub> <mi>T</mi> <mi mathvariant="normal">c</mi> </msub> <mo>/</mo> <msub> <mi>T</mi> <mrow> <mi mathvariant="normal">c</mi> <mn>0</mn> </mrow> </msub> <mo>=</mo> <mo form="prefix">exp</mo> <mrow> <mo>(</mo> <mi>γ</mi> <mo>)</mo> </mrow> <msup> <mrow> <mo>(</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>/</mo> <mi>γ</mi> <mo>−</mo> <msqrt> <mrow> <mi>t</mi> <mo>/</mo> <mn>2</mn> </mrow> </msqrt> <mo>+</mo> <mi>t</mi> <mo>/</mo> <mn>4</mn> <mo>)</mo> </mrow> <mo>/</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>/</mo> <mi>γ</mi> <mo>+</mo> <msqrt> <mrow> <mi>t</mi> <mo>/</mo> <mn>2</mn> </mrow> </msqrt> <mo>+</mo> <mi>t</mi> <mo>/</mo> <mn>4</mn> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mrow> <mn>1</mn> <mo>/</mo> <mi>γ</mi> </mrow> </msup> </mrow> </semantics> </math> with <math display="inline"> <semantics> <mrow> <mi>t</mi> <mo>=</mo> <msub> <mi>R</mi> <mo>□</mo> </msub> <mo>/</mo> <mrow> <mo>(</mo> <mn>4</mn> <mi>π</mi> <msub> <mi>R</mi> <mi mathvariant="normal">Q</mi> </msub> <mo>)</mo> </mrow> </mrow> </semantics> </math> and where the fit coefficient <math display="inline"> <semantics> <mi>γ</mi> </semantics> </math> is related to the elastic scattering time <math display="inline"> <semantics> <mi>τ</mi> </semantics> </math> by <math display="inline"> <semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mo>(</mo> <mi>h</mi> <mo>/</mo> <mrow> <mo>(</mo> <msub> <mi>k</mi> <mi mathvariant="normal">B</mi> </msub> <msub> <mi>T</mi> <mrow> <mi mathvariant="normal">c</mi> <mn>0</mn> </mrow> </msub> <mo>)</mo> </mrow> <mo>)</mo> <mo form="prefix">exp</mo> <mrow> <mo>(</mo> <mo>−</mo> <mi>γ</mi> <mo>)</mo> </mrow> </mrow> </semantics> </math> [<a href="#B31-nanomaterials-08-00442" class="html-bibr">31</a>], and we also treat <math display="inline"> <semantics> <msub> <mi>T</mi> <mrow> <mi mathvariant="normal">c</mi> <mn>0</mn> </mrow> </msub> </semantics> </math> as a fit coefficient, obtaining <math display="inline"> <semantics> <msub> <mi>T</mi> <mrow> <mi mathvariant="normal">c</mi> <mn>0</mn> </mrow> </msub> </semantics> </math> = 13.4 K. (The fit parameter <math display="inline"> <semantics> <mi>γ</mi> </semantics> </math> is related to the fit parameter <math display="inline"> <semantics> <msub> <mi>γ</mi> <mrow> <mo>[</mo> <mn>31</mn> <mo>]</mo> </mrow> </msub> </semantics> </math> in [<a href="#B31-nanomaterials-08-00442" class="html-bibr">31</a>] by <math display="inline"> <semantics> <mrow> <mi>γ</mi> <mo>=</mo> <mo>−</mo> <mn>1</mn> <mo>/</mo> <msub> <mi>γ</mi> <mrow> <mo>[</mo> <mn>31</mn> <mo>]</mo> </mrow> </msub> </mrow> </semantics> </math>.) Inset: Variation of <math display="inline"> <semantics> <mrow> <msub> <mi>T</mi> <mi mathvariant="normal">c</mi> </msub> <mi>d</mi> </mrow> </semantics> </math> with <math display="inline"> <semantics> <msub> <mi>R</mi> <mo>□</mo> </msub> </semantics> </math>; the line shows a fit to <math display="inline"> <semantics> <mrow> <msub> <mi>T</mi> <mi mathvariant="normal">c</mi> </msub> <mrow> <mo>(</mo> <mi mathvariant="normal">K</mi> <mo>)</mo> </mrow> <mo>.</mo> <mspace width="0.166667em"/> <mi>d</mi> <mrow> <mo>(</mo> <mi>nm</mi> <mo>)</mo> </mrow> <mo>=</mo> <mi>A</mi> <msup> <mrow> <mo>[</mo> <msub> <mi>R</mi> <mo>□</mo> </msub> <mrow> <mo>(</mo> <mi mathvariant="sans-serif">Ω</mi> <mo>)</mo> </mrow> <mo>]</mo> </mrow> <mrow> <mo>−</mo> <mi>B</mi> </mrow> </msup> </mrow> </semantics> </math> as applied in [<a href="#B32-nanomaterials-08-00442" class="html-bibr">32</a>].</p> "> Figure 2
<p>Schematic side view cross-sections through nanowire showing the fabrication technologies employed. (<b>a</b>) Fabrication by negative resist, electron-beam lithography (EBL) and reactive ion etching (RIE). (<b>b</b>) Nanowire cut-out using positive resist, EBL and RIE. (<b>c</b>) Nanowire definition by neon focussed ion-beam milling (Ne-FIB).</p> "> Figure 3
<p>Plan-view micrographs of nanowires we have fabricated via three different processes. (<b>a</b>) He-FIB image of a nanowire fabricated using a hydrogen silsesquioxane (HSQ) negative-resist mask. Kinks in the nanowire shape may arise from strain relief of the nanowire resist mask during processing [<a href="#B34-nanomaterials-08-00442" class="html-bibr">34</a>]. Inset: An enlarged view of the part of the image indicated by the upper red box. (<b>b</b>) Scanning electron micrograph of a nanowire fabricated by cut-out using a polymethyl methacrylate (PMMA) mask. (<b>c</b>) He-FIB image of a nanowire defined by Ne-FIB. In all images, light contrast shows the niobium nitride, and dark contrast shows the substrate. Note that not all the images show the narrowest nanowire obtained using this strategy.</p> "> Figure 4
<p><math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> measurements at 4.2 K for five nanowires with widths in the range 20–250 nm in a film of a thickness of 10 nm. (<b>a</b>) <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> at 4.2 K for nanowires of widths of 250 nm, 100 nm and 75 nm. Lines join consecutive points. (<b>b</b>) Same data zoomed-in at low bias and also showing data for nanowires of widths of 50 nm and 25 nm. (<b>c</b>) Data for the three narrowest nanowires on a further expanded scale. Notice that the data for the 50-nm-wide and 75-nm-wide nanowires contain small jumps for <math display="inline"> <semantics> <mrow> <mi>V</mi> <mo><</mo> <mn>20</mn> </mrow> </semantics> </math> mV.</p> "> Figure 5
<p>Measurements on sample NbN81/2. (<b>a</b>) <math display="inline"> <semantics> <mrow> <mi>R</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </semantics> </math>. The inset shows the same data on an expanded scale. (<b>b</b>) <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> at 330 mK. The lines show fits to the form <math display="inline"> <semantics> <mrow> <mi>V</mi> <mo>=</mo> <msub> <mi>V</mi> <mi>i</mi> </msub> <mo form="prefix">sinh</mo> <mrow> <mo>(</mo> <mi>I</mi> <mo>/</mo> <msub> <mi>I</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> </mrow> </semantics> </math>: the dashed line shows the best fit to thermally activated phase-slips (TAPS), with <math display="inline"> <semantics> <mrow> <msub> <mi>V</mi> <mi>TAPS</mi> </msub> <mo>=</mo> <mn>45.7</mn> </mrow> </semantics> </math> mV, and the dashed line shows the best fit as a model of incoherent quantum phase-slips (IQPS), with <math display="inline"> <semantics> <mrow> <msub> <mi>V</mi> <mi>IQPS</mi> </msub> <mo>=</mo> <mn>467</mn> </mrow> </semantics> </math> mV and <math display="inline"> <semantics> <mrow> <msub> <mi>I</mi> <mi>IQPS</mi> </msub> <mo>=</mo> <mn>77.9</mn> </mrow> </semantics> </math> mA. The inset shows the same data on an expanded scale.</p> "> Figure 6
<p><math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> for nanowire NbN65/1 at 320 mK, which has a width of 40 nm and a length of 220 nm and was fabricated using Ne-FIB. The <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> shows possible phase-slip-centre behaviour. Solid lines join consecutive points; arrows show the direction of current sweep; and dashed red lines show resistance multiples of 6.5 kΩ.</p> "> Figure 7
<p>Measurements of sample NbN25/A1. (<b>a</b>) <math display="inline"> <semantics> <mrow> <mi>R</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </semantics> </math>, found by fitting to <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> taken with <math display="inline"> <semantics> <mrow> <mo>|</mo> <mi>I</mi> <mo>|</mo> <mo>≤</mo> <mn>10</mn> </mrow> </semantics> </math> nA. (<b>b</b>) <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> at 330 mK. (<b>c</b>) Low-bias sweep at 330 mK, showing a critical voltage feature.</p> "> Figure 8
<p>Measurements on sample NbN80/1. (<b>a</b>) <math display="inline"> <semantics> <mrow> <mi>R</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> </semantics> </math>. Inset: the same data on an expanded scale showing the low-temperature region. (<b>b</b>) High-bias <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> at 330 mK. (<b>c</b>) <math display="inline"> <semantics> <mrow> <mi>I</mi> <mo>(</mo> <mi>V</mi> <mo>)</mo> </mrow> </semantics> </math> at three temperatures above and below <math display="inline"> <semantics> <msub> <mi>T</mi> <mi mathvariant="normal">c</mi> </msub> </semantics> </math>, 350 mK, 1.92 K and 12.98 K. In all sub-plots, lines join consecutive data points. Voltage- and current-offsets of −1.25 mV, 0.5 mV and −0.28 mV and 5.5 pA, 6.0 pA and 5.5 pA, respectively, have been subtracted from the respective datasets in (c). The slight hysteresis observed in the measurement at 12.98 K is not a property of the sample, but rather an artefact associated with carrying out the measurement relatively rapidly (see <a href="#sec3dot2-nanomaterials-08-00442" class="html-sec">Section 3.2</a>).</p> ">
Abstract
:1. Introduction
2. Results
2.1. Film Characterisation: Changes from Bulk Properties to Thin-Film Behaviour
2.2. From Thin Films to Narrow Nanowires: Nanowire Fabrication
2.3. Spectrum of Nanowire Properties
2.4. Coherent Quantum Phase-Slip Behaviours in NbN Nanowires
3. Discussion
3.1. Fabrication Challenges
3.2. IV Measurement Considerations
4. Materials and Methods
4.1. Film Deposition
4.2. Nanowire Definition
4.3. Other Circuit Components
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Doyle, S.; Mauskopf, P.; Zhang, J.; Monfardini, A.; Swenson, L.; Baselmans, J.; Yates, S.; Roesch, M. A review of the lumped element kinetic inductance detector. Proc. SPIE 2010, 7741. [Google Scholar] [CrossRef]
- Hadfield, R. Single-photon detectors for optical quantum information applications. Nat. Photonics 2009, 3, 696. [Google Scholar] [CrossRef]
- Mooij, J.; Nazarov, Y. Superconducting nanowires as quantum phase-slip junctions. Nat. Phys. 2006, 2, 169–172. [Google Scholar] [CrossRef] [Green Version]
- Hriscu, A.; Nazarov, Y. Coulomb blockade due to quantum phase-slips illustrated with devices. Phys. Rev. B 2011, 83, 174511. [Google Scholar] [CrossRef]
- Tinkham, M. Introduction to Superconductivity, 2nd ed.; McGraw–Hill: New York, NY, USA, 1996. [Google Scholar]
- Chandrasekhar, V.; Webb, R. Single electron charging effects in high-resistance In2O3−x Wires. J. Low Temp. Phys. 1994, 97, 9. [Google Scholar] [CrossRef]
- Haviland, D.; Kuzmin, L.; Delsing, P.; Claeson, T. Observation of the Coulomb blockade of Cooper pair tunnelling in single Josephson junctions. Europhys. Lett. 1991, 16, 103. [Google Scholar] [CrossRef]
- Astafiev, O.; Ioffe, L.; Kafanov, S.; Pashkin, Y.A.; Arutyunov, K.Y.; Shahar, D.; Cohen, O.; Tsai, J. Coherent quantum phase-slip. Nature 2012, 484, 355–358. [Google Scholar] [CrossRef] [PubMed]
- Webster, C.; Fenton, J.; Hongisto, T.; Giblin, S.; Zorin, A.; Warburton, P. NbSi nanowire quantum phase-slip circuits: DC supercurrent blockade, microwave measurements, and thermal analysis. Phys. Rev. B 2013, 87, 144510. [Google Scholar] [CrossRef]
- Hongisto, T.; Zorin, A. Single-charge transistor based on the charge-phase duality of a superconducting nanowire circuit. Phys. Rev. Lett. 2012, 108, 097001. [Google Scholar] [CrossRef] [PubMed]
- Peltonen, J.; Astafiev, O.; Korneeva, Y.P.; Voronov, B.; Korneev, A.; Charaev, I.; Semenov, A.; Golt’sman, G.; Ioffe, L.; Klapwijk, T.; et al. Coherent flux tunneling through NbN nanowires. Phys. Rev. B 2013, 88, 220506. [Google Scholar] [CrossRef] [Green Version]
- De Graaf, S.; Skacel, S.; Hönigl-Decrinis, T.; Shaikhaidarov, R.; Rotzinger, H.; Linzen, S.; Ziegler, M.; Hübner, U.; Meyer, H.; Antonov, V.; et al. Charge quantum interference device. Nat. Phys. 2018. [Google Scholar] [CrossRef]
- Arutyunov, K.; Lehtinen, J.; Rantala, T. The quantum phase-slip phenomenon in superconducting nanowires with high-impedance environment. J. Supercond. Nov. Magn. 2016, 29, 569. [Google Scholar] [CrossRef]
- Kafanov, S.; Chtchelkatchev, N. Single flux transistor: The controllable interplay of coherent quantum phase-slip and flux quantization. J. Appl. Phys. 2013, 114, 073907. [Google Scholar] [CrossRef]
- Goldman, A.; Markovic, N. Superconductor–insulator transitions in the two-dimensional limit. Phys. Today 1998, 39. [Google Scholar] [CrossRef]
- Paalanen, M.; Hebard, A.; Ruel, R. Low-temperature insulating phases of uniformly disordered two-dimensional superconductors. Phys. Rev. Lett. 1992, 69, 1604. [Google Scholar] [CrossRef] [PubMed]
- Bollinger, A.; Dinsmore, R.; Rogachev, A.; Bezryadin, A. Determination of the superconductor–insulator phase diagram for one-dimensional wires. Phys. Rev. Lett. 2008, 101, 227003. [Google Scholar] [CrossRef] [PubMed]
- Lau, C.; Markovic, N.; Bocrath, M.; Bezryadin, A.; Tinkham, M. Quantum phase-slips in superconducting nanowires. Phys. Rev. Lett. 2001, 87, 217003. [Google Scholar] [CrossRef] [PubMed]
- Arutyunov, K.; Golubev, D.; Zaikin, A. Superconductivity in one dimension. Phys. Rep. 2008, 464, 1. [Google Scholar] [CrossRef]
- Altomare, F.; Chang, A.; Melloch, M.; Hong, Y.; Tu, C. Evidence for macroscopic quantum tunneling of phase-slips in long one-dimensional superconducting Al wires. Phys. Rev. Lett. 2006, 97, 017001. [Google Scholar] [CrossRef] [PubMed]
- Makise, K.; Terai, H.; Tominari, Y.; Tanaka, S.; Shinozaki, B. Duality picture of superconductor–insulator transitions on superconducting nanowire. Sci. Rep. 2016, 6, 27001. [Google Scholar] [CrossRef] [PubMed]
- Fenton, J.; Webster, C.; Warburton, P. Materials for superconducting nanowires for quantum phase-slip devices. J. Phys. Conf. Ser. 2011, 286, 012024. [Google Scholar] [CrossRef] [Green Version]
- Mooij, J.; Schön, G.; Shnirman, A.; Fuse, T.; Harmans, C.; Rotzinger, H.; Verbruggen, A. Superconductor–insulator transition in nanowires and nanowire arrays. New J. Phys. 2015, 17, 033006. [Google Scholar] [CrossRef] [Green Version]
- Kautz, R. Chaotic states of rf-biased Josephson junctions. J. Appl. Phys. 1981, 52, 641. [Google Scholar] [CrossRef]
- Kim, H.; Jamali, S.; Rogachev, A. Superconductor–insulator transition in long MoGe nanowires. Phys. Rev. Lett. 2012, 109, 027002. [Google Scholar] [CrossRef] [PubMed]
- Arutyunov, K.; Hongisto, T.; Lehtinen, J.; Leino, L.; Vasiliev, A. Quantum phase-slip phenomenon in ultra-narrow superconducting nanorings. Sci. Rep. 2012, 2, 293. [Google Scholar] [CrossRef] [PubMed]
- Lehtinen, J.; Kemppinen, A.; Mykkänen, E.; Prunnila, M.; Manninen, A. Superconducting MoSi nanowires. Supercond. Sci. Technol. 2017, 31, 015002. [Google Scholar] [CrossRef] [Green Version]
- Nash, C.; Fenton, J.; Constantino, N.; Warburton, P. Compact chromium oxide thin film resistors for use in nanoscale quantum circuits. J. Appl. Phys. 2014, 116, 224501. [Google Scholar] [CrossRef] [Green Version]
- Feigel’man, M.; Ioffe, L.; Kravtsov, V.; Cuevas, E. Fractal superconductivity near localization threshold. Ann. Phys. 2010, 325, 1390. [Google Scholar] [CrossRef]
- Constantino, N.G.N. Disorder in Superconductors in Reduced Dimensions. Ph.D. Thesis, University College London, Gower Street, London, UK, 2016. [Google Scholar]
- Finkel’stein, A. Suppression of superconductivity in homogeneously disordered systems. Phys. B Condens. Matter 1994, 197, 636. [Google Scholar] [CrossRef]
- Ivry, Y.; Kim, C.; Dane, A.; De Fazio, D.; McCaughan, A.; Sunter, K.; Zhao, Q.; Berggren, K. Universal scaling of the critical temperature for thin films near the superconducting-to-insulating transition. Phys. Rev. B 2014, 90, 214515. [Google Scholar] [CrossRef]
- Crauste, O.; Gentils, A.; Couëdo, F.; Dolgorouky, Y.; Bergé, L.; Collin, S.; Marrache-Kikuchi, C.; Dumoulin, L. Effect of annealing on the superconducting properties of a-NbxSi1−x thin films. Phys. Rev. B 2013, 87, 144514. [Google Scholar] [CrossRef]
- Fenton, J.; Burnett, J. Superconducting NbN Nanowires and Coherent Quantum Phase-Slips in DC Transport. IEEE Trans. Appl. Supercond. 2016, 26, 2200505. [Google Scholar] [CrossRef]
- Jesudasan, J.; Mondal, M.; Chand, M.; Kamlapure, A.; Kumar, S.; Saraswat, G.; Bagwe, V.; Tripathi, V.; Raychaudhuri, P. Upper Critical Field and Coherence Length of Homogenously Disordered Epitaxial 3-Dimensional NbN Films. AIP Conf. Proc. 2011, 923, 1349. [Google Scholar] [CrossRef]
- Vanevic, M.; Nazarov, Y. Quantum phase-slips in superconducting wires with weak inhomogeneities. Phys. Rev. Lett. 2012, 108, 187002. [Google Scholar] [CrossRef] [PubMed]
- Kerman, A. Flux–charge duality and topological quantum phase fluctuations in quasi-one-dimensional superconductors. New J. Phys. 2013, 15, 105017. [Google Scholar] [CrossRef] [Green Version]
- Cedergren, K.; Ackroyd, R.; Kafanov, S.; Vogt, N.; Shnirman, A.; Duty, T. Insulating Josephson Junction chains as pinned Luttinger liquids. Phys. Rev. Lett. 2017, 119, 167701. [Google Scholar] [CrossRef] [PubMed]
- Tan, S.; Livengood, R.; Shima, D.; Notte, J.; McVey, S. Gas field ion source and liquid metal ion source charged particle material interaction study for semiconductor nanomachining applications. J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. 2010, 28, C6F15. [Google Scholar] [CrossRef]
- Burnett, J.; Fenton, J. Embedding NbN nanowires into quantum circuits with a neon focused ion beam. IEEE Trans. Appl. Supercond. 2016, 26, 1700104. [Google Scholar] [CrossRef]
- Burnett, J.; Sagar, J.; Kennedy, O.; Warburton, P.; Fenton, J. Low-loss superconducting nanowire circuits using a neon focused ion beam. Phys. Rev. Appl. 2017, 8, 014039. [Google Scholar] [CrossRef]
Sample | Fab Method | Circuit Elements | l (μm) | w (nm) | (kΩ) | (K) | (K) | Behaviour Summary |
---|---|---|---|---|---|---|---|---|
100414/D2 | Cut-out | none | 1 | 250 | ∼2 | ≈7.5 | ≈2 | sc |
100414/D1 | Cut-out | none | 1 | 100 | ∼2 | ≈7.5 | ≈2.5 | sc |
100414/C2 | Cut-out | none | 1 | 75 | ∼2 | ≈7.1 | ≈3 | sc |
100414/C1 | Cut-out | none | 1 | 50 | ∼2 | ≈6.7 | ≈3 | sc |
100414/B2 | Cut-out | none | 1 | 25 | ∼2 | ≈7.2 | ≈4 | sc |
NbN25/A1 | HSQ | none | 18 | 50 | ≈5 | 5.5 | 5 | 300 μV |
NbN65/1 | Ne-FIB | none | 0.22 | 40 | ∼9 | 4 | 1 | sc, PSCs |
NbN80/1 | HSQ | L,R | 10.5 | ≈60 | ≈10 | 5.5 | 2–3 | 5 mV |
NbN81/2 | HSQ | L,R | 10.5 | ≈60 | ≈1 | 8.5 | 2 | sc, IQPS |
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Constantino, N.G.N.; Anwar, M.S.; Kennedy, O.W.; Dang, M.; Warburton, P.A.; Fenton, J.C. Emergence of Quantum Phase-Slip Behaviour in Superconducting NbN Nanowires: DC Electrical Transport and Fabrication Technologies. Nanomaterials 2018, 8, 442. https://doi.org/10.3390/nano8060442
Constantino NGN, Anwar MS, Kennedy OW, Dang M, Warburton PA, Fenton JC. Emergence of Quantum Phase-Slip Behaviour in Superconducting NbN Nanowires: DC Electrical Transport and Fabrication Technologies. Nanomaterials. 2018; 8(6):442. https://doi.org/10.3390/nano8060442
Chicago/Turabian StyleConstantino, Nicolas G. N., Muhammad Shahbaz Anwar, Oscar W. Kennedy, Manyu Dang, Paul A. Warburton, and Jonathan C. Fenton. 2018. "Emergence of Quantum Phase-Slip Behaviour in Superconducting NbN Nanowires: DC Electrical Transport and Fabrication Technologies" Nanomaterials 8, no. 6: 442. https://doi.org/10.3390/nano8060442