BREAD Collaboration Workshop
Harvard University

We are excited to host the next BREAD collaboration workshop at Harvard University in January!
Start: Wednesday, January 14, 9am
End: Friday, January 16, 2026, afternoon
Location:
Harvard University Physics Department
Jefferson Lab 256
It was a pleasure having you all here. Please find below the slides you shared with us. We sent around a separate link with the recordings and pictures.
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08:30
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09:00
Breakfast 30m
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09:00
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09:45
Welcome and Theory
- 09:00
- 09:15
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09:45
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11:55
GigaBREAD and GHz DetectionConvener: Morgan Lynn (UChicago / Harvard)
- 09:45
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10:05
Reflector Mechanical Design and Fridge Integration 25mSpeaker: Alex Buzzi (Harvard)
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10:30
Coffee 20m
- 10:50
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11:15
J-TWPAs 25mSpeaker: Jennifer Wang (MIT)
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11:40
Discussion Time 15m
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12:00
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13:00
Lunch 1h
Boxed Lunches Provided
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13:00
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15:10
QualityBREAD, SlicedBREAD and mm-wave amplifiersConvener: Dr Andrew Sonnenschein (Fermilab)
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13:00
QualityBREAD - Simulations, and W-Band Receiver 25mSpeaker: Gabe Hoshino (UChicago)
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13:25
SlicedBREAD - Idea and Sensitivity 20mSpeaker: I-see Jaidee (Harvard)
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13:45
SlicedBREAD - First Measurements 20m
[for slides see previous talk]
Speaker: Grant McIntyre (Harvard) -
14:05
Dielectric Material Characterization with mm-wave Fabry Perot Cavities 25mSpeaker: Brodi Elwood (Harvard)
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14:30
Dielectric Stack Diplexers and SIS Detectors 25mSpeakers: Dr Edward Tong (Center for Astrophysics | Harvard & Smithsonian), Keara Carter (Center for Astrophysics | Harvard & Smithsonian)
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14:55
Discussion 15m
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13:00
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15:10
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15:35
Coffee 25m
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15:35
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16:00
Other Axion SearchesConvener: Prof. David Miller (UChicago)
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15:35
Fermilab Axion Cavity Experiment with JPA / transmon qbit 25mSpeaker: Morgan Lynn (UChicago / Harvard)
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15:35
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16:00
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16:50
Towards a Large-Scale BREAD programConvener: Prof. David Miller (UChicago)
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16:00
Requirements for an Ultimate Axion Search w/ BREAD 20mSpeaker: Stefan Knirck (Harvard University)
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16:20
Magnet & Facility Options 20mSpeaker: Dr Andrew Sonnenschein (Fermilab)
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16:40
Discussion 10m
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16:00
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17:00
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18:00
Lab Tours: Group 1
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17:00
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18:00
PI Discussions
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18:00
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19:55
Dinner & Posters
Harvard Physics Library
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08:30
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09:00
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08:30
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09:00
Breakfast 30m
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09:00
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09:25
Other Axion Searches
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09:00
MADMAX - Update and Single Photon Detection Plans 25mSpeaker: Juan Maldonado (Max Planck Institute for Physics)
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09:00
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09:25
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09:55
Other Physics Targets for BREADConvener: Stefan Knirck (Harvard University)
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09:25
Other Physics Targets for BREAD (Broadband, Timing, Directionality) 20mSpeaker: Gabe Hoshino (UChicago)
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09:45
Discussion 10m
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09:25
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09:55
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12:10
TeraBREAD and THz SensingConvener: Stefan Knirck (Harvard University)
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09:55
Transition Edge Sensors 25mSpeaker: Dr Rita Sonka (NASA Goddard (Karwan's group))
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10:20
Coffee 20m
- 10:40
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11:05
Cold-Electron Bolometers for broadband sub-cm wave single photon counting (~60GHz) 25mSpeaker: Prof. Karthik Ramanathan (Washington University in St. Louis)
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11:30
Josephson Photonics Devices for BREAD 25m
Josephson photonics refers to the physics of Josephson junctions biased at a DC voltage V below the superconducting gap, interacting with electromagnetic radiation. In this regime, Cooper pairs tunnel inelastically through the junction, exchanging their potential energy 2eV with the electromagnetic environment in the form of photons. Because the junction has no inductance in this voltage state, Josephson photonics devices are not limited by the plasma frequency that constrains most Josephson junction technologies to about 30 GHz. This opens the door to much higher operational frequencies.
We are developing two Josephson photonics devices that could be useful for BREAD:
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Inelastic Cooper Pair Tunneling Amplifier (ICTA), a linear, quantum-limited amplifier [1]. I will present our latest progress in extending ICTA bandwidth to an octave [2] and discuss our roadmap toward ICTAs operating in the W-band (75 to 110 GHz).
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Photon-Number Amplifier, a device multipling the photon number in an incoming mode into n photons in an outgoing mode [3]. Ideally, this process adds no photon noise, enabling detection far below the standard quantum limit. I will share recent experimental results and describe two readout strategies: time-resolved photon counting [4] and spectral resolution.
[1] Near-quantum-limited amplification from inelastic Cooper-pair tunnelling, S. Jebari, F. Blanchet, A. Grimm, D. Hazra, R. Albert, P. Joyez, D. Vion, D. Estève, F. Portier, M. Hofheinz, Nat Electron 1, 223-227.
[2] DC-powered broadband quantum-limited microwave amplifier, N. Nehra, N. Bourlet, A. H. Esmaeili, B. Monge, F. Cyrenne-Bergeron, A. Paquette, M. Arabmohammadi, A. Rogalle, Y. Lapointe, and M. Hofheinz, to appear on arXiv.
[3] Microwave Photon-Number Amplification, R. Albert, J. Griesmar, F. Blanchet, U. Martel, N. Bourlet, M. Hofheinz, Phys. Rev. X 14, 011011 .
[4] Amplification and Detection of Single Itinerant Microwave Photons, L. Danner, M. Hofheinz, N. Bourlet, C. Padurariu, J. Ankerhold, B. Kubala, arXiv:2510.08030v1.
Speakers: Prof. Max Hofheinz (Université de Sherbrooke), Dr Nicolas Bourlet (Université de Sherbrooke) -
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11:55
Discussion 10m
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09:55
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12:10
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12:20
Group Photo
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12:10
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13:10
Lunch 1h
Boxed Lunches Provided
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12:25
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13:10
Lab Tours: Group 2
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13:10
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14:10
Lab Tours: Group 3
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13:10
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14:10
PI Discussions
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14:10
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16:30
TeraBREAD and THz SensingConvener: Morgan Lynn (UChicago / Harvard)
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14:10
SQuAT (Superconducting Quasiparticle-Amplifying Transmons) 25mSpeaker: Dr Alexander Droster (Stanford University/SLAC)
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14:35
WIXARD (WIdeband graphene-based aXion dARk matter quantum Detector) for BREAD and MADMAX 20mSpeaker: Prof. Kin Chung Fong (Northeastern University)
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14:55
Designing a Graphene Microwave single photon detector 20mSpeaker: Prof. Ethan Arnault (Syracuse University)
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15:15
Coffee 10m
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15:25
Single Electrons in a Penning Trap as a meV Single Photon Counter for BREAD 25mSpeaker: Prof. Xing Fan (Harvard)
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15:50
Axion Dark Matter Detection with Axion Quasiparticles 25mSpeaker: Prof. Suyang Xu (Harvard)
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16:15
Discussion 15m
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14:10
- 16:25 → 20:35
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08:30
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09:00
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08:30
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09:00
Breakfast 30m
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09:00
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09:20
Other Physics Targets for BREAD
- 09:00
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09:20
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10:40
InfraBREAD and InfraredConvener: Dr Andrew Sonnenschein (Fermilab)
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09:20
InfraBREAD - Reflector & SNSPD Chcaracterization 30mSpeaker: Dr Christina Wang (Fermilab)
- 09:50
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10:15
Powder Haloscope (remote) 25mSpeaker: Prof. Masha Baryakhtar (University of Washington)
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09:20
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10:40
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11:00
Coffee 20m
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11:00
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12:25
TeraBREAD and THz Sensing: Beyond SensingConvener: Stefan Knirck (Harvard University)
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11:00
Photomixer R&D 20mSpeaker: Dr Emily Perry (Lawrence Berkeley National Laboratory (LBNL) )
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11:40
Fourier Transform Spectrometer Options 25mSpeaker: Dr Ritoban Basu Thakur (JPL)
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12:05
Discussion - Options for Frequency Resolution in BREAD 20m
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11:00
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12:25
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12:40
Closeout 15mSpeakers: Dr Andrew Sonnenschein (Fermilab), Stefan Knirck (Harvard University)
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12:40
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13:40
Lab Tours: Group 4
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12:40
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14:20
Lunch (individual) 1h 40m
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14:00
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18:00
Time for Individual Activites / Meetings
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14:20
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15:50
Student Session: R&D Forum: Grounding, Vibration, ...
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08:30
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09:00