Probing and enhancing the quantum properties of solid-state spins for quantum simulators
DEMITRY FARFURNIK, NORTH CAROLINA STATE UNIVERSITY
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NCSU QUANTUM WORKSHOP
NOVEMBER 16TH, 2023
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Quantum Science and Technology: a New Era
Credit: IBM
Credit: QuTech, Delft
Credit: University of Basel
Computing & Simulation
Networking
Sensing
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Qubits: Base Building Blocks
General State:
Many qubits
Product State:
Entangled State
(Example for n=2: Bell State)
Measuring 1 affects 2
Independent Measurements
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Spin Ensembles Can Simulate Many-Body Dynamics
P. Cappellaro and M. D. Lukin, Phys. Rev. A 80, 032311 (2009)
Squeezed States
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Uncertainty to measure ensemble along a certain direction
Coherent States
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Ensembles of Spins Can be Used as Sensors
{
{
D. Le Sage et al., Nature 496, 486 (2013)
E. Farchi, Y. Ebert, D. Farfurnik et al., SPIN 07, 1740015 (2017)
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Adding a level: Optically-Active Spin Systems
Spin
Photonic
Transitions
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Simulators with Single Photons On-Chip
C. Sparrow et al., Nature 557, 660–667 (2018)
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Simulators with Optically-Active Spins in Cavities
Exact classical simulation so far limited to 2 Cavities and 4 emitters
But can be realized experimentally with optically-active spin systems
Example: Tavis-Cummings-Hubbard Model
Related work: J. Patton et al., All-Photonic Quantum Simulators with Spectrally Disordered Emitters, arXiv:2112.15469
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Simulators using Optically-Active Spins
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Different Approaches for Spin Control
Direct microwave
{
{
Two-Photon
Raman
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Goal: Getting the Best of Both Worlds by Realizing Hybrid Control
1. Microwave Control:
- Application of thousands of pulses of quantum information processing
2. Optical Control:
- Diffraction limited
- Straightforward polarization of nuclear baths
+
?
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Optical Control Enables Noise Spectroscopy (quantum dots)
Dynamics under pulse sequences
Numerical
analysis
Experimentally extracted noise spectra
D. Farfurnik et al., All-Optical Noise Spectroscopy of a Solid-State Spin, Nano Lett. 23, 1781-1786 (2023)
B = 1.2 T
B = 2 T
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K. Huang, D. Farfurnik, A. Seif, M. Hafezi, and Y-K. Liu, Random Pulse Sequences for Noise Spectroscopy, arXiv:2303.00909
Compressed Sensing of the noise spectrum
Random Pulse Sequences
Number of resources compared to standard techniques
Compressed Sensing Enables Next Generation Noise Spectroscopy
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Dynamical Decoupling Can Suppress Noise
Spin-echo pulse
More frequent pulses (dynamical decoupling) suppress higher frequency noise terms
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D. Farfurnik et al., Phys. Rev. B 92, 060301(R) (2015)
Dynamical Decoupling Protocols Preserve Arbitrary Spin States (NV Centers)
- Long coherence time of arbitrary spin state
- Thousands of control pulses
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Summary & Outlook
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Acknowledgements
Collaborators:
- Prof. Dan Stancil, Prof. Daryoosh Vashaee, Prof. Dror Baron
- Prof. Edo Waks, Prof. Mohammad Hafezi, Prof. Ron Walsworth, Prof. Yi-Kai Liu, Dr. Alireza Seif, Dr. Alessandro Rastelli (UMD)
- Dr. Allan Bracker, Dr. Samuel Carter (Naval Research Lab)
- Prof. Dmitry Budker (JGU Mainz)
- Prof. Nir Bar-Gill, Prof. Alex Retzker (Hebrew University)
Funding Sources:
Graduate, undergraduate, and postdoc research positions available!
Visit us at research.ece.ncsu.edu/farfurnik/ or email me at dfarfur@ncsu.edu
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Photonic Fabrication in Direct Bandgap Semiconductors
H,Singh*, D. Farfurnik* et al., Optical Transparency Induced by a Largely Purcell Enhanced Quantum Dot in a Polarization-Degenerate Cavity, Nano Lett. 22, 7959-7964 (2022) *- Equal Contributors.
Straightforward fabrication
Diode for deterministic
Charging & charge noise
mitigation
Straightforward fabrication
Etching of “sacrificial layer”
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New System to Study: Family of SiC Defects
S. Majety et al., J. Appl. Phys. 131, 130901 (2022)
Studied
Not widely studied
Efficient emission of single photons at telecom wavelength -> excellent candidates for quantum communication
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Scalable Spins Can Leverage the Quantum out of Sensing
P. Cappellaro and M. D. Lukin, Phys. Rev. A 80, 032311 (2009)
Highly Entangled
(“Squeezed”) States
Option 1: Applying NMR-
based pulse sequences
(Hamiltonian Engineering)
D. Farfurnik, Y. Horowicz, and N. Bar-Gill, Physical Review A 98, 033409 (2018)
K. I. O. Ben ‘Attar*, D. Farfurnik*, and N. Bar-Gill, Physical Review Research 2, 013061 (2020)
*-equal contributors
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Option 2: Leveraging
dissipation from
a cavity
E. G. Dalla Torre et al., Phys. Rev. Lett. 110, 120402 (2013)
Photonic Properties of NV Centers are not Great
Goal: build spin-photon interface
for the generation of entanglement
Issues
Challenging to fabricate high quality cavities
Optical emission is inefficient (large phonon sideband)
K. Beha et al., J. Nanotechnol. 3, 895–908 (2012)
Approach: use optically-active spins with better photonic properties
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Criteria for an Efficient Spin-Photon Interface
2. Efficient access to external light
Cavity
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Photonic Crystal Cavities Offer Strong Coupling but Poor Optical Access
Far Field Emission Mode
Z. Luo et al., Nano Lett. 19, 7072-7077 (2019)
“Strong coupling regime”, but access to light is poor
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Photonic Cavities Can Provide Photon Switching Capabilities
“Bullseye” cavity
Emission Mode
Cavity Reflectivity
H,Singh*, D. Farfurnik* et al., Optical Transparency Induced by a Largely Purcell Enhanced Quantum Dot in a Polarization-Degenerate Cavity, Nano Lett. 22, 7959-7964 (2022) *- Equal Contributors.
“Bullseye” cavity
Q factors ~ 1,200
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Future Direction: Photonic Repeaters Using Medium-Q Cavities
Requirement:
optical transition resonant with the cavity & one optical transition off resonant
Present “Bullseye” cavity
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Promising Solid-state system : Quantum Dot Molecules
Two vertically-stacked quantum dots
(also possible in Telecom, but haven’t studied yet)
fields: long spin coherence times, but requires
alternative approach for spin control
Related works: J.M. Daniels at al., Phys. Rev. B 88, 205307 (2013), K. X. Tran et al., Phys. Rev. Lett. 129, 027403 (2022),
Y. Tsuchimoto et al., PRX Quantum 3, 030336 (2022), D. Farfurnik et al., Phys. Rev. Applied 15, L031002 (2021)