Microwave Atom-optics
Faced with the task of making quantum systems accessible at the human scales, the field of quantum technologies is exploding with possibilities.
In our lab, we are exploring these ideas along a number of different fronts, all while using our understanding of atomic systems to help us along the way.
Microwave technologies
Over the past few years, we have been exploring the possibilities for using microwaves to interact with atoms, with an eye towards possible applications in microwave-to-optical quantum information transduction, or direct microwave quantum memories. Towards this goal, we have been building an arsenal of technologies using atoms, including working with microwave cavities in collaboration with the Davis Lab.
Ultracold plus low-temperature
In an ambitious new project in collaboration with the Davis lab and other partners from across Alberta, we are building an apparatus in which we couple a laser-cooling and trapping machine (to make ultracold gases) to a dilution refrigerator (which can bring macro- and meso-scopic objects down to low temperatures.
Papers
Custom engineering the atomic ground state populations through microwave-assisted optical pumping
A warm atom sample is used as a non-linear medium to facilitate three-wave mixing between optical and microwave signals, and the resulting coherent microwave-to-optical conversion maps a microwave signal to a large, tunable 550(30) MHz range of optical frequencies using room-temperature 87Rb atoms. With simultaneous conversion of a multi-channel input microwave field to corresponding optical channels, we demonstrate phase-correlated amplitude control of select channels, resulting in complete extinction of one of the channels, providing an analog to a frequency domain beam splitter across five orders of magnitude in frequency.
Benjamin D. Smith, Bahar Babaei, Andal Narayanan, Lindsay J. LeBlanc
Comm. Phys. 6, 338 (2023)
[Journal link] [arxiv.org:2305.19221]
Custom engineering the atomic ground state populations through microwave-assisted optical pumping
Using the strong microwave field available in a 3D enclosed cavity, microwaves can be used to couple ground hyperfine levels in the rubidium atom, which modifies the effects of optical pumping and allows for custom atomic polarizations without needing to physically modify the system's geometry. With this ground state atomic polarization, applications to microwave-controlled switching and polarization rotation are possible.
A. Tretiakov, C. A. Potts, Y. Y. Lu, J. P Davis, L. J. LeBlanc [arxiv.org:2110.10673]
Dielectric properties of machinable polymers for microwave cavities in hybrid quantum systems
To determine the best machinable polymers for use inside microwave cavities (often as support structures), we measured the cavity response for three common polymer materials and report the dielectric and loss coefficients.
M. Ruether, C.A. Potts, J.P. Davis and L.J. LeBlanc. [arxiv.org:2104.10237]
In collaboration with the Davis group, who are experts in building microwave cavities, we developed a system to enhance microwave-to-atom coupling in room-temeperature atomic vapours, and use this to facilitate a radio-signal conversion from a microwave to an optical carrier.
A. Tretiakov, C. A. Potts, T. S. Lee, M. J. Thiessen, J. P. Davis, L. J. LeBlanc. [arxiv.2001.03150]
Microwave-driven interactions in atoms are probed using optical light using the "double-resonance" feature of Rb atoms. Resonance features of the process let us calibrate the strength of the microwave fields using the atoms -- as an "atomic candle."
A. Tretiakov and L. J. LeBlanc, Phys. Rev. A 99, 043402 (2019).[Journal Link][arxiv:1902.01971]
Atoms magnetically coupled to nanoscale oscillators
Oscillating nanostructures with embedded magnetism, whether as permanent magnets or electrical currents, can interact with the magnetic dipole of an atom. A neat cooling scheme can be realised by combining optical pumping and adiabatic sweeps.
A. Tretiakov and L.J. LeBlanc, Phys. Rev. A 94, 043802 (2016)[Journal Link][arxiv:1605.03126]
On-chip cavities for applications in atomic cavity QED
In work led by the DeCorby and Davis groups, optical microcavities resonant with the 87Rb D2 transition were fabricated and studied, with an eye towards a strongly coupled atom + cavity.
C.A. Potts, A. Melnyk, H. Ramp, M.H. Bitarafan, D. Vick, L.J. LeBlanc, J.P. Davis, R.G. DeCorby. Appl. Phys. Lett. 108, 041103 (2016).[Journal Link][arxiv:1602.03344]
Posters and other information
In our new project, we are building a cold atoms machine coupled to a dilution refrigerator to study the interactions between cold atoms and cryogenic quantum devices.