Detecting Axion Dark Matter with Superconducting Qubits Akash - - PowerPoint PPT Presentation
Detecting Axion Dark Matter with Superconducting Qubits Akash Dixit, Aaron Chou, Dave Schuster University of Chicago avdixit@uchicago.edu 1 Axion Dark Matter Broken U1 symmetry introduced to solve Strong CP problem (Peccei & Quinn)
Akash Dixit, Aaron Chou, Dave Schuster University of Chicago avdixit@uchicago.edu
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problem (Peccei & Quinn)
than experiment (~100m)
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∼ g ∂a(t) ∂t B0(x) · A ∼ Ja · A
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Use axion induced current to drive cavity
f ∼ ma
Currently operating ~1GHz, R&D ~10GHz
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Harmonic Oscillator + Two Level System
Stark Shift : cavity-qubit coupling detuning
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H = ωca†a + ωqσz + 2g2 ∆ a†aσz
∆ = ωq − ωc g χ = g2 ∆
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Axion induced current pumps cavity with photon Cavity occupation shifts qubit transition Excite qubit at shifted frequency Measure flipped qubit by monitoring cavity line shift
H = ωca†a + (ωq + 2g2 ∆ a†a)σz H = (ωc + 2g2 ∆ σz)a†a + ωqσz
Cavity Design
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H = ωca†a
10mm
Cavity Mode
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Custom Atom
Harmonic Oscillator (LC) + nonlinearity (Josephson Junction)
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H = ωqσz
Design your own
ωq = E1 − E0
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Not pictured:
Fluorine Etcher Optical Direct Writer Electron Beam Lithography
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1 m m
2 µ m × 2 µ m
Nb optically patterned and etched to form dipole arms and capacitive pads Qubits on wafer
12mm
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Josephson Junction
1 µm
20µm
a. b. c.
253 nm 260 nm
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Dipole arms + qubit location in cavity set qubit-cavity coupling g ∼ d · E(x)
Hint = 2g2 ∆ a†aσz
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ωq
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Axion induced current pumps cavity with photon Cavity occupation shifts qubit transition Excite qubit at shifted frequency Measure flipped qubit by monitoring cavity line shift
H = ωca†a + (ωq + 2g2 ∆ a†a)σz H = (ωc + 2g2 ∆ σz)a†a + ωqσz
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ωq
ωq − χ
ωq − 2χ
Cavity occupation shifts qubit transition
|n = 0i |n = 1i |n = 2i χ ∼ 15 MHz
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π
ωq − χ
|n = 1i
Apply pi pulse at shifted qubit frequency
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Measure excited qubit by monitoring cavity line shift
χ ∼ 15 MHz
Shift penalties of standard quantum limit by counting photons rather than absorbing them I make solid state superconducting detectors with customizable interactions with an EM environment I employ quantum computing techniques/devices for dark matter cosmology experiment
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References
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[1] D.I. Schuster. Circuit Quantum Electrodynamics. PhD thesis, Yale University, 2007. [2] B.R. Johnson. Controlling Photons in Superconducting Electrical Circuits. PhD thesis, Yale University, 2011. [3] S. K. Lamoreaux, K. A. van Bibber, K. W. Lehnert, and G. Carosi. Analysis of single-photon and linear amplifier detectors for microwave cavity dark matter axion searches. Phys. Rev. D, 88:035020, Aug 2013. [4] V Bouchiat, D Vion, P Joyez, D Esteve, and M H Devoret. Quantum coherence with a single cooper pair. Physica Scripta, 1998(T76):165, 1998. [5] Jens Koch, Terri M. Yu, Jay Gambetta, A. A. Houck, D. I. Schuster, J. Majer, Alexandre Blais, M. H. Devoret, S. M. Girvin, and R. J. Schoelkopf. Charge-insensitive qubit design derived from the cooper pair
[6] Simon E. Nigg, Hanhee Paik, Brian Vlastakis, Gerhard Kirchmair, S. Shankar, Luigi Frunzio, M. H. Devoret,
108:240502, Jun 2012. [7] http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.105.173601 [8] https://arxiv.org/pdf/1206.1265.pdf
Cavity
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