Bench-top cooling of a microwave mode using an optically pumped spin refrigerator
File(s)
Accepted version
Author(s)
Wu, Hao
Mirkhanov, Shamil
Ng, Wern
Oxborrow, Mark
Type
Journal Article
Abstract
We experimentally demonstrate the temporary removal of thermal photons from a microwave
mode at 1.45 GHz through its interaction with the spin-polarized triplet states of photo-excited
pentacene molecules doped within a p-terphenyl crystal at room temperature. The crystal functions electromagnetically as a narrow-band cryogenic load, removing photons from the otherwise
room-temperature mode via stimulated absorption. The noise temperature of the microwave mode
dropped to 50+18
−32 K (as directly inferred by noise-power measurements) while the metal walls of the
cavity enclosing the mode remained at room temperature. Simulations based on the same system’s
behavior as a maser (which could be characterized more accurately) indicate the possibility of the
mode’s temperature sinking to ∼10 K (corresponding to ∼140 microwave photons).These observations, when combined with engineering improvements to deepen the cooling, identify the system
as a narrow-band yet extremely convenient platform —free of cryogenics, vacuum chambers and
strong magnets— for realizing low-noise detectors, quantum memory and quantum-enhanced machines (such as heat engines) based on strong spin-photon coupling and entanglement at microwave
frequencies.
mode at 1.45 GHz through its interaction with the spin-polarized triplet states of photo-excited
pentacene molecules doped within a p-terphenyl crystal at room temperature. The crystal functions electromagnetically as a narrow-band cryogenic load, removing photons from the otherwise
room-temperature mode via stimulated absorption. The noise temperature of the microwave mode
dropped to 50+18
−32 K (as directly inferred by noise-power measurements) while the metal walls of the
cavity enclosing the mode remained at room temperature. Simulations based on the same system’s
behavior as a maser (which could be characterized more accurately) indicate the possibility of the
mode’s temperature sinking to ∼10 K (corresponding to ∼140 microwave photons).These observations, when combined with engineering improvements to deepen the cooling, identify the system
as a narrow-band yet extremely convenient platform —free of cryogenics, vacuum chambers and
strong magnets— for realizing low-noise detectors, quantum memory and quantum-enhanced machines (such as heat engines) based on strong spin-photon coupling and entanglement at microwave
frequencies.
Date Issued
2021-07-29
Date Acceptance
2021-06-04
Citation
Physical Review Letters, 2021, 127, pp.1-6
ISSN
0031-9007
Publisher
American Physical Society
Start Page
1
End Page
6
Journal / Book Title
Physical Review Letters
Volume
127
Copyright Statement
© 2021 American Physical Society
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Identifier
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.053604
Grant Number
EP/K037390/1
EP/M020398/1
EP/V048430/1
Subjects
Science & Technology
Physical Sciences
Physics, Multidisciplinary
Physics
PHOTO-EXCITED TRIPLET
BLACKBODY-RADIATION
RYDBERG ATOMS
STATE
PENTACENE
MASER
RESONANCE
AMPLIFIER
CRYSTAL
CAVITY
General Physics
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Publication Status
Published
Date Publish Online
2021-07-29