- Экспериментально продемонстрировано, что свехпроводниковая схема на основе ячейки куперовских пар ведёт себя как квантовая двухуровневая система. Суперпозиция двух квантовых состояний системы контролируется внешним сигналом. Состояние системы измеряется с помощью дополнительного зондового туннельного перехода. Наблюдаются квантовые осцилляции между двумя макроскопическими состояниями такой системы. Таким образом создан твердотельный квантовый бит.
- Предложена, проанализирована и реализована схема из двух связанных зарядовых джозефсоновских кубитов. Экспериментально продемонстрирована квантовая динамика такой системы. На основе такой схемы продемонстрирована работа квантовой логической ячейки CNOT.
- Реализован и изучен одноэлектронный транзистор с резистивной связью. Показано, что коэффициент усиления по напряжению такого устройства определяется эффектом перегрева электронной подсистемы устройства и поэтому значительно ниже ожидаемого для выбранных параметров устройства.
- Достигнуто значение рабочей температуры одноэлектронного транзистора, рекордное для устройств, изготовленных с помощью стандартной электронной литографии.
- Экспериментально продемонстрирован эффект синхронного переноса электронов через десять электронных насосов на основе одноэлектронных транзисторов типа сверхпроводник - изолятор - нормальный металл - изолятор - сверхпроводник, работающих в параллель, с соответствующим увеличением выходного тока.
- Экспериментально исследован эффект внешнего электромагнитного окружения на свойства одиночных туннельных переходов и одноэлектронных транзисторов. Показано, что резонансы во внешней цепи проявляются в транспорте обоих устройств. Использование шунтирующей ёмкости вблизи устройств позволяет подавить резонансы, а также существенно уменьшить ток утечки в одиночных переходах типа нормальный металл - изолятор - сверхпроводник, что повышает точность работы электронных насосов на основе таких переходов.
- Разработана оригинальная методика изготовления металлических наномеханических резонаторов, позволяющая интегрировать их в наноэлектронные устройства, такие как одноэлектронные транзисторы, зарядовые и потоковые джозефсоновские кубиты. Задетектирован высокочастотный механический резонанс острова одноэлектронного транзистора в его постоянном токе. Измерены температурная зависимость частоты и затухания резонаторов.
1.Manninen A.J., Pashkin Yu.A., Korotkov A.N., Pekola J.P. Observation of thermally excited charge transport modes in a superconducting single electron transistor // Europhys. Lett. 1997. V. 39. P. 305-310.
2.Farhangfar Sh., Toppari J.J., Pashkin Yu .A ., Manninen A.J., Pekola J.P. Experiments on tunneling in small normal-metal junctions influenced by dissipative environment: Critical comparison to the theories of quantum fluctuations // Europhys. Lett. 1998. V. 43. P. 59-64.
3.Pashkin Yu . A . , Nakamura Y . , Ts a i J.S. Metallic resistively coupled single-electron transistor // Appl. Phys. Lett. 1999. V. 74. P 132-134.
4.Pashkin Yu . A . , Pekola J.P. , Kuzmin L.S. Chromium based small area tunnel junctions and single electron transistors // J. Vac. Sci. Technol. B. 1999. V. 17. P. 1413-1416.
5.Pashkin Yu . A . , Nakamura Y. , Tsai J.S. Implementation of single-electron transistor with resistive gate // Jpn. J. Appl. Phys. 1999. V. 38. No 1B. Part 1. P. 406-409.
6.Zorin A.B., Lotkhov S .V., Pashkin Yu . A . , Zangerle H., Krupenin V.A ., Weimann T. , Scherer H., Niemeyer J. Highly sensitive electrometers based on single Cooper pair tunneling // J. Superconductivity. 1999. V. 12. P. 747-755.
7.Pashkin Yu . A . , Nakamura Y. , Tsai J.S. Coulomb blockade in resistively coupled single-electron transistor: dependence on bias conditions // Jpn. J. Appl. Phys. 1999. V. 38. No. 4B. P. 2466-2469.
8.Nakamura Y. , Pashkin Yu . A . , Tsai J.S. Coherent control of macroscopic quantum states in a single-Cooper-pair box // Nature. 1999. V. 398. P. 786-788.
9.Nakamura Y. , Pashkin Yu .A . , Tsai J.S. Quantum coherence in a single-Cooper-pair box: experiments in the frequency and time domain // Physica B. 2000. V. 280. P. 405-409.
10. Pashkin Yu .A . , Nakamura Y. , Tsai J.S. Room-temperature Al single- electron transistor made by electron-beam lithography // Appl. Phys. Lett. 2000. V. 76. P. 2256-2258.
11.Tsai J.S., Nakamura Y. , Pashkin Yu . A . Superconducting single-Cooper-pair box as quantum bit // Physica C. 2001. V. 357-360. P. 1-6.
12.Tsai J.S., Nakamura Y., Pashkin Yu . A . Qubit utilizing charge-number state in a superconducting nanostructure // Quantum Information and Computation. 2001. V . 1. P. 124-128.
13.Tsai J.S, Nakamura Y. , Pashkin Yu . A . Superconducting single-Cooper-pair box quantum bit with multi-gate-pulse operation // Physica C. 2002. V. 367. P. 191-196.
14.Solin S.A., Hines D.R., Tsai J.S, Pashkin Yu.A., Chung S.J., Goel N., Santos M.B. Room temperature extraordinary magnetoresistance of non- magnetic narrow-gap semiconductor/metal composites: application to read- head sensors for ultra-high density magnetic recording // IEEE Trans. Magn. 2002. V. 38. No 1. P. 89-94.
15.Solin S.A., Hines D.R., Rowe A.C.H., Tsai J.S., Pashkin Yu.A., Chung S.J., Goel N., Santos M.B. Nonmagnetic semiconductors as read-head sensors for ultra-high- density magnetic recording // Appl. Phys. Lett. 2002. V. 80. P. 4012-4014.
16.Nakamura Y., Yamamoto T. , Tsai J.S., Pashkin Yu . A . Coherent manipulations of charge-number states in a Cooper-pair box // Physica Scripta. 2002. V. T102. P. 155-161.
17.Pashkin Yu . A . , Yamamoto T. , Astafiev O., Nakamura Y. , Av e r i n D .V., Tsai J.S. Quantum oscillations in two coupled charge qubits // Nature. 2003. V. 421. P. 823-826.
18.Ootuka Y., Kurosawa T. , Kanda A., Pashkin Yu ., Tsai J.S. Tunnel spectroscopy of small Al particle // Physica E. 2003. V . 18. P. 19-20.
19.Solin S.A., Hines D.R., Rowe A.C.H., Tsai J.S, Pashkin Yu .A . Nanoscopic magnetic field sensor based on extraordinary magnetoresistance // J. Vac. Sci. Technol. B. 2003. V. 21. P. 3002-3006.
20.Yamamoto T. , Pashkin Yu . A . , Astafiev O., Nakamura Y., Tsai J.S. Demonstration of conditional gate operation using superconducting charge qubits // Nature. 2003. V. 425. P. 941-944.
21.Pashkin Yu .A . , Tilma T. , Averin D .V., Astafiev O., Yamamoto T. , Nakamura Y. , Nori F. , Tsai J.S. Entanglement of two coupled charge qubits // Int. J. Quantum Information. 2003. V. 1. No 4. P. 421-426.
22.Astafiev O., Pashkin Yu.A., Yamamoto T., Nakamura Y., Tsai J.S. Single-shot measurement of the Josephson charge qubit // Phys. Rev. B 2004. V. 69 P. 180507:1-4(R).
23.Пашкин Ю.А., Астафьев О.В., Yamamoto T., Nakamura Y., Tsai J.S. Джозефсоновские твердотельные кубиты // УФН. 2004. Т. 47 С. 943-944.
24.Tsai J.S., Yamamoto T., Pashkin Yu.A., Astafiev O., Nakamura Y. Coupled Josephson quantum bits // Proc. SPIE Int. Soc. Opt. Eng. 2004. V. 5472. P. 11-18.
25.Pashkin Yu.A., Astafiev O., Yamamoto T., Nakamura Y., Averin D.V., Tilma T., Nori F., Tsai J.S. Coherent dynamics of two coupled superconducting charge qubits // Proc. SPIE Int. Soc. Opt. Eng. 2005. V. 5833. P. 116-126.
26.Pashkin Yu.A., Astafiev O., Yamamoto T., Nakamura Y., Averin D.V., Tilma T., Nori F., Tsai J.S. Coherent manipulation of coupled Josephson charge qubits // Physica C. 2005. V. 426-431. P. 1552-1560.
27.Im H., Pashkin Yu.A., Yamamoto T., Astafiev O., Nakamura Y., Tsai J.S. Characterization of ultrasmall all-Nb tunnel junctions with ion gun oxidized barriers // Appl. Phys. Lett. 2006. V. 88. P. 112113:1-3.
28.Astafiev O., Pashkin Yu.A.,Yamamoto T., Nakamura Y., Tsai J.S. Temperature square dependence of the low frequency 1/f charge noise in the Josephson junction qubits // Phys. Rev. Lett. 2006. V. 96 P. 137001:1-4.
29.Yamamoto T., Nakamura Y., Pashkin Yu.A., Astafiev O., Tsai J.S. Parity effect in superconducting single-electron transistors with a special gap profile controlled by the film thickness // Appl. Phys. Lett. 2006. V. 88. P. 212509:1-3.
30.Im H., Pashkin Yu.A., Yamamoto T., Astafiev O., Nakamura Y., Tsai J.S. Characterization of all-Nb nanodevices fabricated by electron beam lithography and ion beam oxidation // J. Vac. Sci. Technol. B. 2007. V. 25. P. 448-454.
31.Li T.F., Pashkin Yu.A., Im H., Astafiev O., Nakamura Y., Tsai J.S. Low-frequency charge noise in suspended aluminum single-electron transistors // Appl. Phys. Lett. 2007. V. 91. P. 033107:1-3.
32.Savin A.M., Meschke M., Pekola J.P., Pashkin Yu.A., Li T.F., Im H., Tsai J.S. Parity effect in Al and Nb single-electron transistors in a tunable environment // Appl. Phys. Lett. 2007. V. 91. P. 063512:1-3.
33.Li T.F., Pashkin Yu.A., Astafiev O., Nakamura Y., Tsai J.S., Im H. High frequency metallic nanomechanical resonators // Appl. Phys. Lett. 2008. V. 92. P. 043112:1-3.
34.Yamamoto T., Watanabe M., You J.Q., Pashkin Yu.A., Astafiev O., Nakamura Y., Nori F., Tsai J.S. Spectroscopy of superconducting charge qubits coupled by a Josephson inductance // Phys. Rev. B. 2008. V. 77. P. 064505:1-3.
35.Muhonen J.T., Niskanen O.A., Meschke M., Pashkin Yu.A., Tsai J.S., Sainiemi L., Franssila S., Pekola J.P. Electronic cooling of a submicron-sized metallic beam // Appl. Phys. Lett. 2009. V. 94. P. 073101:1-3.
36.KemppinenA., Kafanov S., Pashkin Yu.A., Tsai J.S., Averin D.V., Pekola J.P. Experimental investigation of hybrid single-electron turnstiles with high charging energy // Appl. Phys. Lett. 2009. V. 94. P. 172108:1-3.
37.Pashkin Yu.A., Astafiev O., Yamamoto T., Nakamura Y., Tsai J.S. Josephson charge qubits: a brief review // Quantum Inf. Process. 2009. V. 8. P. 55-80.
38.Jung H., Kim Y., Jung K., Im H., Pashkin Yu.A., Astafiev O., Nakamura Y., Lee H., Miyamoto Y., Tsai J.S. Potential barrier modification and interface states formation in metal-oxide-metal tunnel junctions // Phys. Rev. B. 2009. V. 80. P. 125413:1-4.
39.Kafanov S., Kemppinen A., Pashkin Yu.A., Meschke M., Tsai J.S., Pekola J.P. Single-electronic radio-frequency refrigerator // Phys. Rev. Lett. 2009. V. 103. P. 120801:1-4.
40.Maisi V.F., Pashkin Yu.A., Kafanov S., Tsai J.S., Pekola J.P. Parallel pumping of electrons // New J. Phys. 2009. V. 11. P. 113057:1-9.
41.Pekola J.P., Maisi V.F., Kafanov S., Chekurov N., Kemppinen A., Pashkin Yu.A., Saira O.-P., Mцttцnen M., Tsai J.S. Photon assisted tunneling as an origin of the Dynes density of states // Phys. Rev. Lett. 2010. V. 105. P. 026803:1-4.
42.Pashkin Yu.A., Li T.F., Pekola J.P., Astafiev O., Knyazev D.A., Hoehne F., Im H., Nakamura Y., Tsai J.S. Detection of mechanical resonance of a single-electron transistor by direct current // Appl. Phys. Lett. 2010. V. 96. P. 263513:1-3.
43.Im H., Pashkin Yu.A., Kim Y., Li T.F., Jung K., Astafiev O., Tsai J.S. Subgap leakage and interface states in superconductor–insulator–superconductor tunnel junction // Physica C. 2010. V. 470. P. S832-S833.
44.Hoehne F., Pashkin Yu.A., Astafiev O., Faoro L., Ioffe L.B., Nakamura Y., Tsai J.S. Damping in high-frequency metallic nanomechanical resonators // Phys. Rev. B. 2010. V. 81. P. 184112:1-5.
45.Pashkin Yu . A . , Im H., Leppдkangas J., Li T.F., Astafiev O., Abdumalikov A.A., Thuneberg E., Tsai J.S. Charge transport through ultrasmall single and double Josephson junctions coupled to resonant modes of the electromagnetic environment // Phys. Rev. B. 2011. V. 83. P. 020502(R):1-4.
II. Публикации в прочих журналах, трудах конференций и сборниках
1.Pashkin Yu .A., Farhangfar Sh., Toppari J.J., Pekola J . P. Experimental investigation of the influence of electromagnetic environment on charging effects in ultra-small tunnel junctions // Abstracts of Invited and Contributed Papers of the Int. Symposium “Nanostructures: Physics and Technology”, 23–27 June 1997, St.Petersburg, Russia. P 484-487.
2.Pashkin Yu ., Nakamura Y. , Ts a i J.S. Implementation of single-electron transistor with resistive gate // Proceedings of the 1998 International Symposium on Formation, Physics and Device Application of Quantum Dot Structures (QDS´98), 31 May–4 June 1998, Sapporo, Japan. P. 406-409.
3.Pashkin Yu ., Nakamura Y. , Ts a i J.S. Observation of Coulomb blockade in resistively coupled single-electron transistor // Extended abstracts of the 1998 International Conference on Solid State Devices and Materials (SSDM 1998), 7– 10 September 1998, Hiroshima, Japan. P . 2 0 4 -205.
4.Pashkin Yu., Nakamura Y. , Ts a i J.S. Implementation of single-electron transistor with resistive gate // Abstracts of the 2000 International Symposium on Formation, Physics and Device Application of Quantum Dot Structures (QDS 2000), 10–14 September 2000, Sapporo, Japan.
5.Pashkin Yu . A., Nakamura Y., Ts a i J.S. Al single-electron transistor: room-temperature operation and energy level quantization // Abstracts of the European Meeting on the Technology and Application of SET-Devices, 5–6 June 2000, Braunschweig, Germany. P. 18.
6.Ts a i J.S., Nakamura Y ., Pashkin Yu . A . The first solid-state qubit // Digest of the Device Research Conf. (58th DRC), 19-21 June 2000, Denver, CO, USA. P. 93-94.
7.Pashkin Yu .A . , Nakamura Y., Ts a i J. S. Room-temperature single-electron transistor made by e-beam lithography // Abstracts of the 12th Symp. of the Materials Research Society of Japan, 7–8 December 2000, Kawasaki, Japan. P. 160.
8.Nakamura Y., Pashkin Yu . A., Ts a i J.S. Quantum-state interference in a Cooper-pair box // in “Macroscopic Quantum Coherence and Quantum Computing”. eds. D .V . Averin, B. Ruggiero, and P. Silvestrini. New Yo r k : Kluwer Academic/Plenum, 2000. P . 17-24.
9.Ts a i J.S., Nakamura Y., Pashkin Yu . A . Qubit utilizing charge-number state in a superconducting nanostructure // Proceedings of the 1st Int. Conference on Experimental Implementation of Quantum Computation, 16–19 January 2001, Sydney, Australia. ed. R.G. Clark. Princeton: Rinton Press, 2001. P. 105-110.
10.Pashkin Yu., Nakamura Y. , Ts a i J.S. Possibility of aluminum single- electron devices and superconducting coherence // Abstracts of the International Workshop on “Superconducting nano-electronics devices (SNED)” 28 May–1 June 2001, Naples, Italy.
11.Pashkin Yu . A . , Nakamura Y., Yamamoto T. , Ts a i J.S. Possibility of aluminum single-electron devices and superconducting coherence // Proceedings of the International Workshop on Superconducting Nano- Electronics Devices. eds. J. Pekola, B. Ruggiero and P. Silvestrini. New York: Kluwer Academic/Plenum, 2001. P. 97-103.
12.Pashkin Yu ., Yamamoto T., Astafiev O., Nakamura Y. , Av e r i n D.V., Ts a i J.S. Quantum oscillations in two coupled charge qubits // Abstracts of the International Symposium “Carrier interactions and spintronics in nanostructures (CISN 2003),”10–12 March 2003, Atsugi, Japan. P. 47.
13.Ts a i J.S., Pashkin Yu . A., Yamamoto T. , Astafiev O., Nakamura Y., Av e r i n D.V. Coupled Josephson quantum bit // Proceedings of 11th International Symposium “Nanostructures: Physics and Technology”, 23–28 June 2003, St. Petersburg, Russia, P.145-147.
14.Pashkin Y u . A . , Astafiev O., Yamamoto T. , Nakamura Y . , Av e r i n D.V . , Ts a i J.S. Cou pling t wo ch arge q ubits // NEC R&D. 2 003. V. 44. P . 273-277.
15. Pashkin Yu ., Yamamoto T., Astafiev O., Nakamura Y. , Av e r i n D., Ts a i J.S. Quantum oscillations in two coupled charge qubits // Extended abstracts of the 9th Int. Superconductive Electronics Conference, 7–11 July 2003, Sydney, Australia.
16.Ts a i J.S., Yamamoto T. , Nakamura Y., Pashkin Yu .A., Astafiev O. Josephson quantum bit // Solid State Physics. 2003. V. 38. No.11. P. 45-56 (in Japanese).
17.Pashkin Yu., Yamamoto T., Astafiev O., Nakamura Y. , Averin D., Ts a i J.S. Quantum oscillations in two coupled charge qubits // Extended abstracts of the 2003 International Conference on Solid State Devices and Materials (SSDM2003), 16–18 September 2003, Tokyo, Japan.
18.Ts a i J.S, Pashkin Yu ., Yamamoto T., Astafiev O., Nakamura Y. , Av e r i n D. Coupled Josephson charge qubits // Abstracts of ERATO Conference on Quantum Information Science, 4–6 September 2003, Kyoto, Japan. P. 7-8.
19.Pashkin Yu . , Yamamoto T. , Astafiev O., Nakamura Y . , Ts a i J.S. Quantum coherence and entanglement of two coupled superconducting charge qubits // Abstracts of IV International workshop on “Macroscopic quantum coherence and computing (MQC2),” 7–10 June 2004, Naples, Italy.
20.Yamamoto T. , Pashkin Yu ., Astafiev O., Nakamura Y ., Ts a i J.S. Conditional gate operation in superconducting charge qubits // Abstracts of IV International workshop on “Macroscopic quantum coherence and computing (MQC2),” 7–10 June 2004, Naples, Italy.
21.Pashkin Y u . A . , Yamamoto T . , Astafiev O., Nakamura Y . , A v e r i n D.V . , T s a i J.S. Coherent manipulation of coupled Josephson qubits // Abstracts of the 17th Int. Symposium on Superconductivity, 23–25 November 2004, Niigata, Japan. P. 150.
22.Pashkin Y u . A., Yamamoto T . , Astafiev O., Nakamura Y . , A v e r i n D.V . , Ti l ma T . , Nori F. , Ts a i J.S. Solid-state Josephson charge qubits // Abstracts of the Joint Workshop on Superconductivity. 1–2 December 2004, Osaka, Japan. P. 40-41.
23.Pashkin Yu. Superconducting nanostructures as quantum bits // Proceedings of the 37th ISTC Japan workshop on advanced Nanomaterials in Russia/CIS, 12–13 December 2005, Tsukuba, Ibaraki, Japan.
24.Yamamoto T. , Pashkin Yu . A ., Astafiev O., Nakamura Y., Ts a i J.S. Conditional gate operation in superconducting charge qubits // in “Quantum Computing in Solid-State Systems”. eds. B. Ruggiero, P. Delsing, C. Granata, Y. Pashkin, P. Silvestrini. New York: Springer, 2006. P. 10-18.
25.Pashkin Yu .A . Controllable coupling of superconducting charge qubits // Abstracts of the 2006 Taiwan International Conference on Superconductivity and 8th Workshop on Low-Temperature Physics, 31 July–4 August 2006, Yi-Lan, Taiwan. P. 31.
26.Im H., Pashkin Yu.A., Yamamoto T., Astafiev O., Nakamura Y., Tsai J.S. Fabrication of ultrasmall all-Nb tunnel junction devices with ion beam oxidized barriers // J. Korean Physical Society. 2006. V. 48. P. 1560-1564.
27.Пашкин Ю.А., Ли Т.Ф., Астафьев О., Князев Д., Цай Дж.Ш. Наномехани-ка одноэлектронного транзистора // Труды XIV Международного симпозиума «Нанофизика и наноэлектроника», 15–19 марта 2010 г., Нижний Новгород. С. 211-212.
28.Pashkin Yu ., Li T. F. , Pekola J., Knyazev D., Hoehne F., Astafiev O., Nakamura Y. , Ts a i J.S. Conventional single-electron transistor as a detector of its nanomechanical motion // Abstracts of the Int. Conf. on Nanoscience and Nanotechnology (ICONN 2010), 22–26 February 2010, Sydney, Australia.