Our group has developed techniques to reliably fabricate small feature sizes in increasingly complex materials (both metals and semiconductors) in order to explore quantum effects at submicron length scales. These quantum phenomena are of interest in their own right, but could also lead to applications in electronic and optical devices, which may exploit the wavefunction and spin of the electron. Our current research focuses quantum optics on artificial quantum systems, quantum phenomena in highly disordered superconducting films and wires, hybrid normal metal-superconductor systems, semiconductor heterostructures and quantum dots, terahertz detectors, nano magnetics.
- NationalPhysical Laboratory
- RHUL Millikelvin Laboratory
- Chalmers University
- Loughborough University
Our group has developed techniques to reliably fabricate small feature sizes in increasingly complex materials (both metals and semiconductors) in order to explore quantum effects at submicron length scales.
These quantum phenomena are of interest in their own right, but could also lead to applications in electronic and optical devices, which may exploit the wavefunction and spin of the electron.
Our current research focuses quantum optics on artificial quantum systems, quantum phenomena in highly disordered superconducting films and wires, hybrid normal metal-superconductor systems, semiconductor heterostructures and quantum dots, terahertz detectors, nano magnetics.
The Nanophysics and Nanotechnology group consists of five academic staff with expertise in all aspects of the fabrication and measurement of nanostructures; this experience is matched by processing, SuperFab, and low temperature measurement facilities.
In the group we have developed techniques to reliably fabricate small feature sizes in increasingly complex materials (principally metals, but also semiconductors) in order to explore quantum effects at submicron length scales.
We have collaborations with experimental and theoretical groups around the world, and there are opportunities (both PhD and MSc) to work in the group.
Charge quantum interference device and applications
The goal of the research is to develop the technology for a new class of quantum devices – Charge Quantum Interference Device (CQUID) ; demonstrate its operation, particularly as a new type of low-noise sensor of electric charge; and study other devices related to this technology based on the Coherent Quantum Phase Slip (CQPS) effect. The CQUID will detect electric charge with ultrahigh sensitivity and, differently from single-electron transistors (SETs), will have a suppressed back-action due to coherent flux flow. It also could lead to a distinct type of superconducting qubit  . A major practical impact of the research is expected in quantum metrology: Based on the quantum interference and coherent flux tunnelling attained in CQUIDs, the quantum current standard utilising CQPS can be developed.
S. E. de Graaf, S. T. Skacel, T. Hoenigl-Decrinis, R. Shaikhaidarov, H. Rotzinger, S. Linzen, M. Ziegler, U. Hübner, H.-G. Meyer, V. Antonov, E. Il’ichev, A. V. Ustinov, A. Ya. Tzalenchuk and O. V. Astafiev. Charge quantum interference device. Nature Physics 14, 590–594 (2018).
O. V. Astafiev, L. B. Ioffe, S. Kafanov, Yu. A. Pashkin, K. Yu. Arutyunov, D. Shahar, O. Cohen, J. S. Tsai. Coherent quantum phase slip. Nature 484, 355-358 (2012)
Microwave Quantum Optics
Superconducting quantum systems (artificial atoms) have been recently successfully used to demonstrate on-chip effects of quantum optics with single atoms in the microwave range. In particular, a well-known effect of four wave mixing could reveal a series of features beyond classical physics, when a non-linear medium is scaled down to a single quantum scatterer. We study the phenomenon of quantum wave mixing (QWM) on a single superconducting artificial atom. In the QWM, the spectrum of elastically scattered radiation is a direct map of the interacting superposed and coherent photonic states. Moreover, the artificial atom visualises photon-state statistics, distinguishing coherent, one- and two-photon superposed states with the finite (quantised) number of peaks in the quantum regime .
A Dmitriev, R Shaikhaidarov, V Antonov, T Hoenigl-Decrinis, and O Astafiev, Quantum wave mixing and visualisation of coherent and superposed photonic states in a waveguide, Nature Comm., 8, 1352 (2017)
Remote terahertz spectroscopy is a formidable and rewarding tool which would find a wide range of applications. It can be used for security and health screening, express analysis of gas composition, material and liquid identification. We study remote spectral terahertz system based on array of plasmonic semiconductor detectors coupled to the compact cryocooler. Plasmonic operation of the detectors allows to limit influence of background terahertz radiation, and to be responsive only to radiation of spectral sources illuminating the scene. At the temperature of compact cryocooler, between 70K and 80K, detectors in the array have a surprisingly narrow lines of sensitivity, FWHM 5-10 GHz, in the spectral range of experiment with a typical responsivity of 0.01 A/W. The effect is due to combination of the detector design and bow-tie planar metallic antennae resonances. Detectors in the array are a narrow conductive channels, defined in a two-dimensional electron gas of high mobility GaAs/AlGaAs heterostructure by mesa design and gating with negative voltage .
FIG. 1. Cryogenic spectral imaging system. Array of terahertz detectors is coupled to the cold finger of compact cryocooler (6). Radiation of THz sources (1) transmitted/reflected by Li2NbO3 crystal is collected by PTFE lens (2) and guided by waveguide to the array of detectors. The array is fixed back to back of Si lens, top of (5). The Si lens is integrated to a standard 20 pin package. The attenuation of the optical system is 35Db. The electronics box (4) enables to address any of 14 detectors in the array. Vacuum can (3) is evacuated down to 10-5 mTorr (shown in disassembled form). Array is cooled down from 300K to 70K in 40 minutes. System demonstrated continuous stable operation for more than a month.
1. R. Shaikhaidarov, V Antonov, A. Casey, A. Kalaboukhov, S. Kubatkin, Y. Harada, K. Onomitsu, A. Tzalenchuk, and A. Sobolev, Detection of coherent terahertz radiation from a high-temperature superconductor Josephson junction by a semiconductor quantum dot detector, Phys. Rev. Applied, 5, 024010 (2016)
|Professor Oleg Astafiev||Professor|
|Professor Victor Petrashov||Professor|
|Dr Vladimir Antonov||Reader|
|Dr James Nicholls||Reader|
|Dr Rais Shaikhaidarov||Postdoctoral Research Assistant|
|Mr Ilya Antonov||PhD student|
|Mr Robb Putock||PhD student|
|Mr Thomas Vincent||PhD student|
|Mr Stefanos Dimitriadis||PhD student|
|Mr Christopher Beauchamp||PhD student|
Hoenigl-Decrinis, Teresa (PhD 2018)
Sahafi, Pardis (PhD 2018)
Corte-Leon, Hector (PhD 2017)
Eless, Viktoria (PhD 2017)
Wren, Thomas (PhD 2016)
Shelly, Connor (PhD 2015)
Pelling, Stephen (PhD 2014)
Panchal, Vishal (PhD 2014)
Marsh, Richard (PhD 2013)
Davis, Raymond (PhD 2013)
Luke Simkins (PhD 2012)
Rees, David (PhD 2010)
Exarchos, Michael (PDRA 2009)
Lindstrom, Tobias (PDRA 2010)
Kleinschmidt, Peter (PhD 2007)
Hashiba, Hideomi(PhD 2006)
Magnetic Imaging Using Geometrically Constrained Nano-Domain Walls, H. Corte-León, L. A. Rodríguez, M. Pancaldi, C. Gatel, D. Cox, E. Snoeck, V Antonov, P. Vavassori, and O. Kazakova, Nanoscale, (2019)
Probing the nanoscale origin of strain and doping in graphene-hBN heterostructures
T. Vincent, V. Panchal, T. Booth, S. R. Power, A.-P. Jauho, V Antonov, O. Kazakova, 2D Materials, 6, 015022 (2019) https://doi.org/10.1088/2053-1583/aaf1dc
Mixing of coherent waves in a single three-level artificial atom,
T. H. Hoenigl-Decrinis, I. V. Antonov, R. Shaikhaidarov, V. Antonov, , A. Y. Dmitriev, O. V. Astafiev,
Physical Review A, 98(4), 041801 (2018)
Charge quantum interference device
de Graaf, S. E., Skacel, S. T., Hönigl-Decrinis, T., Shaikhaidarov, R., Rotzinger, H., Linzen, S., Ziegler, M., Hübner, U., Meyer, H. G., Antonov, V., Il’ichev, E., Ustinov, A. V., Tzalenchuk, A. Y. & Astafiev, O. V.
Nature Physics. 14, p. 590-594 (2018)
Quantum Regime of a Two-Dimensional Phonon Cavity,
A Bolgar, J. Zotova, D. Kirichenko, I. Besedin, A. Semenov, R. Shaikhaidarov, O. Astafiev, Physical Review Letters. 120, 223603 (2018)
Magnetically induced transparency of a quantum metamaterial composed of twin flux qubits
Astafiev, O. et al,
Nature Communications. 9, 150 (2018)
Quantum wave mixing and visualisation of coherent and superposed photonic states in a waveguide
Dmitriev, A., Shaikhaidarov, R., Antonov, V., Hoenigl-Decrinis, T. & Astafiev, O., Nature Communications. 8, 1352 ( 2017)
Quantum Optics on Artificial Quantum Media
Hönigl-Decrinis, T., 2018, PhD Thesis
Domain wall spintronics in novel magnetic nanostructures
Corte-León, H., 2018, PhD Thesis
Quantum near-field scanning microwave microscopy for debugging quantum circuits
Near-field scanning microwave microscopy (NSMM) is a technique where Atomic Force Microscopy (AFM) for nanoscale topographic imaging is combined with microwaves to non-invasively study the complex conductivity of materials at the nanoscale. At the National Physical Laboratory (NPL) in Teddington a unique instrument is currently being developed: The first NSMM that operates in the quantum regime. This fulfils an important need, in particular for the development of quantum computing with superconducting circuits. Here microscopic material defects limit the coherence times of qubits. This poses a difficult challenge for the field and we need more information about the nature of these defects in order to be able to remove them. The unique quantum NSMM would be capable of individually interrogating these defects and pinpoint their location in a quantum circuit. The quantum NSMM can also be applied to study a wide range of quantum devices, from small sensors to large scale quantum circuits, to debug and improve their performance.
To reach the quantum regime the NSMM must operate very low temperatures (<50mK) in a dilution refrigerator, and at ultralow power: in the single microwave photon regime. We recently demonstrated that we are sensitive to dielectric contrast even under these extreme conditions (see figure 1). NPL is now looking for a talented PhD candidate to take this microscope truly into the quantum regime and for the first time demonstrate microwave imaging of coherent quantum effects with nanoscale resolution.
The majority of the project will involve improving and operating an existing AFM-based NSMM in a cryogen-free dilution refrigerator at NPL. This also involves micro-fabrication of superconducting NSMM probes and samples for imaging, both at RHUL (in the new SuperFab cleanroom) and with international collaborators. The successful doctorate will have the opportunity to use this new tool to study a wide range of systems important for future quantum technologies.
For further information please contact: Dr. Sebastian de Graaf (firstname.lastname@example.org) or Dr. Vladimir Antonov (email@example.com)