LT » Kvantti

Kvantti

Our group is part of the effort in nanoelectronics in the Low Temperature Laboratory.

The group is doing research in fields such as quantum information and quantum-level effects in superconducting devices, quantum coherent matter, and interaction of electromagnetic fields with nano-structured materials.


Note: the logo represents the Bloch-sphere trajectories of two qubits operated as a CNOT gate using an optimized sequence of microwave pulses. See Superconducting quantum circuits for more details.


Contents

Members:


Research:

Superconducting quantum circuits

Electromagnetic fields interacting with nano-structured materials

Quantum coherent matter


Active collaborations:

  • A. J. Leggett, University of Illinois at Urbana-Champaing
  • A. Houck, Princeton University
  • J. Mayer and J. Schmiedmayer, Technical University Vienna
  • R. Healey, University of Arizona


Publications:

  1. Pirkkalainen, J.-M., Cho, S.U., Li, J., Paraoanu, G.S., Hakonen, P.J., and Sillanpää, M.A., "Hybrid circuit cavity quantum electrodynamics with a micromechanical resonator", Nature, 494, 211–215 (2013). [DOI]

  2. Li, J., Silveri, M.P., Kumar, K.S., Pirkkalainen, J.-M., Vepsäläinen, A., Chien, W.C., Tuorila, J., Sillanpää, M.A., Hakonen, P.J., Thuneberg, E.V., and Paraoanu, G.S., "Motional averaging in a superconducting qubit", Nature Communications, 4, 1422 (2013). [DOI]

  3. Kumar, K.S., and Paraoanu, G.S., "Designing quantum gates using the genetic algorithm", 400, 022101 (2012). [DOI]

  4. Li, J., Sillanpää, M.A., Paraoanu, G.S., and Hakonen, P.J., "Pure dephasing in a superconducting three-level system", Journal of Physics: Conference Series, 400, 042039 (2012). [DOI]

  5. Paraoanu, G.S., "Interferometers from single-atom mirrors", Journal of Physics: Conference Series, 400, 042050 (2012). [DOI]

  6. Li, J., and Paraoanu, G. S., "Dynamical decoupling of superconducting qubits", Journal of Physics: Conference Series, 338, 012010 (2012). [DOI]

  7. Anghel, D.V., Delion, D., and Paraoanu, G.S., "Advanced many-body and statistical methods in mesoscopic systems (preface)", Journal of Physics: Conference Series, 338, 011001 (2012). [DOI]

  8. Li, J., Paraoanu, G.S., Cicak, K., Altomare, F., Park, J.I., Simmonds, R.W., Sillanpaa, M.A. and Hakonen, P.J., "Dynamical Autler-Townes control of a phase qubit", Scientific Reports, 2, 645 (2012). [DOI]

  9. Paraoanu, G.S., Healey, R., "Non-local creation of a macroscopic angular momentum", International Journal of Theoretical Physics, 51, 1783 (2012). [DOI]

  10. Chalapat, K., Chekurov, N., Li, J., and Paraoanu, G. S., "Ion-beam assisted self-assembly of metallic nanostructures", Nuclear Instruments and Methods in Physics Research B, 272, 202-205 (2012). [DOI]

  11. Paraoanu, G.S., "Quantum Computing: Theoretical versus Practical Possibility", Physics in Perspective, 13, 359–372 (2011). [DOI]

  12. Li, J., Paraoanu, G.S., Cicak, K. Altomare, F., Park, J.I., Simmonds, R.W., Sillanpää, M.A., and Hakonen, P.J., "Decoherence, Autler-Townes effect, and dark states in two-tone driving of a three-level superconducting system", Physical Review B, 84, 104527 (2011). [DOI]

  13. Paraoanu, G.S., "Extraction of information from a single quantum", Physical Review A, 83, 044101/1-4 (2011). [DOI]

  14. Paraoanu, G.S., "Generalized partial measurements", EPL, 93, 64002/1-4 (2011). [DOI]

  15. Paraoanu, G.S., "Realism and Single-Quanta Nonlocality", Foundations of Physics, 41, Paraoanu GS (2011). [DOI]

  16. Kumar K.S., and Paraoanu, G.S., "A quantum no-reflection theorem and the speeding up of Grover's search algorithm", Journal of Physics: Conference Series, 93, 20005/1-4 (2011). [DOI]

  17. Chalapat, K., Paraoanu, G.S., Du, Z., Tervo, J., Nefedov, I., and Tretyakov, S., "Unity absorbance layers - optimal design criteria", Fourth Internation Congress on Advanced Electromagnetic Materials in Mocrowaves and Optics, 279-281 (2010). [URL]

  18. Heikkinen, M.O.J., Massel, F., Kajala, J., Leskinen, M.J., Paraoanu, G.S., and Törmä, P., "Spin-asymmetric Josephson effect", Physical Review Letters, 105, 225301 (2010). [DOI]

  19. Timonen, J.V.I., Ras, R.H.A., Ikkala, O., Oksanen, M., Lehtiniemi, R., Heino, M., Seppälä, E., Chalapat, K., Li, J., and Paraoanu, G.S., [In Book] Magnetic nanocomposites at microwave frequencies, Trends in Nanophysics (2010). [DOI]

  20. Paraoanu, G.S., [In Book] Theoretical aspects of quasiparticle excitations for Bose-Einstein condensates in lattice potentials, Quantum Mechanics (2010). [URL]

  21. Kuhn, T. and Paraoanu, G.S., [In Book] Electronic and thermal sequential transport in metallic and superconducting two-junction arrays, Trends in Nanophysics (2010). [DOI]

  22. Paraoanu, G.S., "Fluorescence interferometry", Physical Review A, 82, 023802 (2010). [DOI]

  23. Li, J. and Paraoanu, G.S., "Decay of entanglement in coupled, driven systems with bipartite decoherence", The European Physical Journal D, 56, 255-264 (2010). [DOI]

  24. Li, J. and Paraoanu, G.S., "Generation and propagation of entanglement in driven coupled-qubit systems ", New Journal of Physics, 11, 113020/1-3 (2009). [DOI]

  25. Sillanpää, M.A., Li, J., Cicak, K., Altomare, F., Park, J.I., Simmonds, R.W., Paraoanu, G.S., and Hakonen, P.J., "Autler-Townes Effect in a Superconducting Three-Level System", Physical Review Letters, 103, 193601/4 (2009). [DOI]

  26. Chalapat, K., Sarvala, K., and Paraoanu, G.S., "Wideband reference-plane invariant method for measuring electromagnetic parameters of materials", IEEE Transactions on Microwave Theory and Techniques, 57, 2257-2267 (2009). [DOI]

  27. Li, J., Chalapat, K., and Paraoanu, G.S., "Measurement-induced entanglement of two superconducting qubits", Journal of Physics: Conference Series, 150, 022051 (2009). [DOI]

  28. Toppari, J.J., Kühn, T., Halvari, A.P., and Paraoanu, G.S., "Method for finding the critical temperature of the island in a SET structure ", Journal of Physics: Conference Series, 150, 022088 (2009). [DOI]

  29. Paraoanu, G.S., "Evolution of fragmented states ", Journal of Physics: Conference Series, 150, 032079 (2009). [DOI]

  30. Rinkiö, M., Johansson, A., Paraoanu, G.S., and Torma, P., "High-speed memory from carbon nanotube field-effect transistors with high-k gate dielectric", Nano Letters, 9, 643-647 (2009). [DOI]

  31. Kallioinen, J., Hassan, M.R., Paraoanu, G.S., and Korppi-Tommola, J., "Dye-Sensitized Nanostructured TiO2 Film Based Photoconductor", Journal of Photochemistry and Photobiology A: Chemistry, 195, 352-356 (2008). [DOI]

  32. Paraoanu, G.S., "Phase coherence and fragmentation in weakly interacting bosonic gases", Physical Review A, 77, 04165/1-4 (2008). [DOI]

  33. Li, J., Chalapat, K., and Paraoanu, G.S., "Entanglement of superconducting qubits via microwave fields: Classical and quantum regimes", Physical Review B, 78, 064503/1-17 (2008). [DOI]

  34. Paraoanu, G.S., "Localization of the relative phase via measurements", Journal of Low Temperature Physics, 153, 285-293 (2008). [DOI]

  35. Li, J., Chapalat, K., and Paraoanu, G.S., "Enhancement of sudden death of entangelemt for driven qubits", Journal of Low Temperature Physics, 153, 294-303 (2008). [DOI]


Equipment:

  • S.H.E. dilution refrigerator in electromagnetically shielded room
  • high-frequency electronics


Open positions:


Summer students (2010): there are currently two main research directions which you can join, depending on your interests and skills:

  • QED (quantum electrodynamics) with superconducting qubits and cavities. We study the quantum dynamics and entanglement properties of qubits in coplanar waveguide cavities. These systems are relevant for tasks such as processing of information in future quantum processors. Your summer research project can be either experimental or theoretical (note: theoretical projects would require a background in quantum physics).
  • Nano-structured materials in microwave fields. This direction aims at extracting information about the physical properties of nanoparticles and films, especially those having magnetic properties. Your project will be experimental and it involves collaborating with industry (Nokia Research Center), and groups in the Applied Physics Department (Molecular Materials and Nanospin). Potential candidates should have a background in classical electromagnetism.
  • These positions have been closed.


Ph.D. position (2009): we are currently looking for a Ph.D. student to start in 2009. The announcement can be found here: Ph.D. position

  • This position is now closed.


Contact:

paraoanu [at] cc.hut.fi

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