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1Towards a fully integrated quantum optical chip
V. Kovalvuk1'2*. I. Venediktov21, K. Sedykh21, D. Kobtsev21, A. Golikov3'4, A. Prokhodtsov1'4, A. Kuzin1'5. I. Florya1'3, V. Galanova1'5, R. Kasimov1'3, S. Hydyrova1'6, T. Krivenkov1,
E. Sheveleva3'7, G. Goltsman2'7
1-Laboratory of Photonic Gas Sensors, University of Science and Technology MISIS, 119049 Moscow, Russia 2- National Research University Higher School of Economics, 109028 Moscow, Russia
3- Moscow State Pedagogical University, 119991 Moscow, Russia
4- National Research University MIET, 124498 Zelenograd, Russia
5- Center for Photonics and Engineering, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia 6- Bauman Moscow State Technical University, 105005 Moscow, Russia 7- Russian Quantum Center, 121205 Moscow, Russia
* kovaliuk.vv@misis.ru
Over the past few decades, quantum technologies have opened up new possibilities for the world, including quantum key distribution [1] that allows secure communications, quantum metrology [2] that allows more accurate measurements than the classical ones, and quantum lithography [3] that allows the fabrication of devices with dimensions much smaller than the wavelength of light. However, the most anticipated quantum technology is a quantum computer, which promises exponentially faster computations for a certain class of problems [4]. Currently, the most common platforms for the physical implementation of quantum bits (qubits) are those based on superconductors, neutral atoms, ions, and photons. Due to their unique characteristics: a large number of degrees of freedom for encoding information (phase, frequency, polarization, angular momentum, etc.), as well as the ability to move over long distances in optically transparent media, photons are considered the most promising basis for a quantum computer. The first demonstrations of photon-based quantum data processing were made on an optical table, but further scaling is impossible without transferring the elements to a chip. The creation of such a chip (or quantum photonic circuit) requires the combination of three main functional blocks: a photon source block, a logic block, and a single-photon detector block. Currently, the most advanced technology of these three blocks is the hybrid integration of superconducting detectors [5] with optical waveguides. The report considers several levels of integration of such detectors in the way of creating scalable devices. The first level is the integration of the detector with various photonic materials. Since the first demonstration in 2011 [6], to date, several research groups have demonstrated superconducting single-photon detectors on waveguides made of silicon, silicon nitride, polycrystalline diamond, lithium niobate on an insulator, etc. The second level of integration includes the combination of detectors with more complex devices: AWG demultiplexers, photonic crystal waveguides, and planar echelettes. At this level, the devices can be used not only as components of quantum optical devices but also as separate devices, namely single-photon spectrometers that record spectral and temporal information about the objects under study. The third level of integration is associated with devices that combine single-photon sources, logical elements, and detectors. Several schemes and approaches based on the use of quantum dots, nanotubes or nonlinear four-wave mixing have been demonstrated so far, but all suffer from low system efficiency or difficult scalability [7]. Work in this direction can be of a breakthrough nature; therefore, it is actively carried out throughout the world, but requires high-tech nanofabrication and access to clean rooms.
[1] N. Gisin, G. Ribordy, W. Tittel, H. Zbinden, Quantum cryptography, Reviews of modern physics, 74(1), 145, (2002).
[2] V. Giovannetti, S. Lloyd, L. Maccone, Quantum-enhanced measurements: beating the standard quantum limit, Science, 306(5700), 13301336, (2004).
[3] A.N. Boto, P. Kok, D.S. Abrams, S.L. Braunstein, C.P. Williams, J.P. Dowling, Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit, Physical Review Letters, 85(13), 2733, (2000).
[4] J.L. O'Brien, Optical quantum computing, Science, 318(5856), 1567-1570, (2007).
[5] G.N. Gol'tsman, O. Okunev, G. Chulkova, A. Lipatov, A. Semenov, K. Smirnov, ... & R. Sobolewski, Picosecond superconducting singlephoton optical detector, Applied physics letters, 79(6), 705-707, (2001).
[6] W.H. Pernice, C. Schuck, O. Minaeva, M. Li, G.N. Goltsman, A.V. Sergienko, H.X. Tang, High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits, Nature communications, 3(1), 1325, (2012).
[7] S. Khasminskaya, F. Pyatkov, K. Slowik, S. Ferrari, O. Kahl, V. Kovalyuk, ... & W.H. Pernice, Fully integrated quantum photonic circuit with an electrically driven light source, Nature Photonics, 10(11), 727-732, (2016).
