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Atomic test of higher-order interference

MetadataDetails
Publication Date2020-05-18
JournalPhysical review. A/Physical review, A
AuthorsKai Sheng Lee, Zhao Zhuo, Christophe Couteau, David Wilkowski, Tomasz Paterek
InstitutionsSorbonne Université, Centre National de la Recherche Scientifique
Citations4
AnalysisFull AI Review Included

Technical Documentation & Analysis: Atomic Test of Higher-Order Interference

Section titled “Technical Documentation & Analysis: Atomic Test of Higher-Order Interference”

This document analyzes the research paper “An atomic test of higher-order interference” (arXiv:1911.12953v1) which proposes a high-precision quantum foundations experiment using atomic interferometry. The analysis focuses on extracting critical material requirements and aligning them with 6CCVD’s advanced MPCVD diamond capabilities to support and extend this research.


This research proposes a novel, high-precision test of the Born rule by measuring the Sorkin parameter ($S_{3}$) using a three-path atomic Ramsey interferometer based on 87Sr atoms.

  • Application Domain: Quantum foundations, high-precision metrology, and advanced quantum simulation.
  • Core Achievement: Proposes a scheme capable of achieving a precision level ($\kappa$) down to $10^{-5}$, representing an order of magnitude improvement over previous state-of-the-art optical and nuclear magnetic resonance (NMR) experiments ($10^{-4}$).
  • Methodology: Replaces spatial slits with superposition of three energy eigenstates (tripod configuration) in 87Sr atoms held in a far-off-resonant optical 3D lattice.
  • Key Components: Requires highly stable optical components, precise magnetic field control ($10^{-2}$ T), and rapid, coherent laser manipulation (Tritter operation time $\tau = 44$ ”s).
  • Material Requirement: The stability and thermal management required for the high-intensity laser systems and integrated magnetic coils necessitate the use of high-purity, high-thermal-conductivity substrates, making MPCVD diamond an ideal enabling technology.
  • Robustness: The setup is inherently robust against common systematic errors (e.g., imperfect tritter coherence) because the Sorkin parameter $S_{3}$ vanishes for canonical quantum mechanics regardless of the initial state or measurement.

The following hard data points define the operational parameters and performance targets of the proposed atomic interferometer setup using 87Sr.

ParameterValueUnitContext
Target Precision ($\kappa$)$10^{-5}$DimensionlessProjected figure of merit for testing higher-order interference.
Atomic Isotope87SrN/AFermionic strontium used for the tripod energy configuration.
External Magnetic Field$10^{-2}$TApplied to induce Zeeman shifts ($\delta$).
Ground State Zeeman Shift ($\delta$)$2\pi \times 18.2$kHzShift used in the free evolution time $T$.
Tritter Transition Wavelength689nmIntercombination line 1S0 $\rightarrow$ 3P1.
Excited State Linewidth ($\Gamma$)$2\pi \times 7.5$kHzUsed in spontaneous emission blocking calculations.
Rabi Frequency ($\Omega$)$2\pi \times 0.1$MHzUsed for generalized Raman transitions (Tritter).
Detuning ($\Delta$)$2\pi \times 1$MHzChosen to be much larger than linewidth ($\Gamma$).
Tritter Operation Time ($\tau$)44”sTime required to prepare an even superposition state.
Blocker $\pi$-pulse Time5”sUsed for spontaneous emission blocking method.
Total Atom Sample Size> $10^{10}$AtomsProjected total sample size over one week of operation.

The experiment is structured as a Ramsey interferometer operating in the energy domain, utilizing a four-level system (three ground states $|1\rangle, |2\rangle, |3\rangle$ and one excited state $|e\rangle$).

  1. Initial State Preparation: 87Sr atoms are laser-cooled and loaded into a far-off-resonant optical 3D lattice. Atoms are prepared in a practically pure ground state $|1\rangle$ via optical pumping or stimulated Raman adiabatic passage (STIRAP).
  2. Tritter Operation ($U_{\tau}$): Generalized Raman transitions, driven by three lasers coupling the ground states to the excited state $|e\rangle$, are used to create a coherent superposition of the three ground states. The operation time is precisely set to $\tau = 44$ ”s based on the chosen Rabi frequency ($\Omega$) and detuning ($\Delta$).
  3. Slit Blocking Analog: Various methods are proposed to simulate blocking the energy paths:
    • State Transfer: Transferring the blocked population into a long-lived state outside the tripod subspace (e.g., metastable 3P0 states).
    • Dephasing: Applying a dephasing map $D_{j}(\rho)$ to remove coherences to the blocked state, while preserving population.
    • Spontaneous Emission (Preferred): Coupling the blocked ground state $|j\rangle$ to an excited state $|e_{j}\rangle$ using a resonant laser, allowing the population to spontaneously decay incoherently to all ground states, effectively removing the blocked path coherence.
  4. Free Evolution: The remaining atoms evolve freely for time $T$ under the influence of the external magnetic field, which dictates the energy differences ($\delta$).
  5. Closing Tritter ($U_{\tau}^{-1}$): A second tritter operation closes the interferometer loop, maximizing contrast.
  6. Final Measurement: Population measurement of the initial ground state $|1\rangle$ is performed to determine the probability of detection ($P_{c}$). The experiment is repeated for all combinations of blocking to calculate the Sorkin parameter $S_{3}$.

The proposed atomic interference experiment demands materials with exceptional optical quality, thermal stability, and the capacity for integrated micro-fabrication. 6CCVD’s MPCVD diamond products are uniquely positioned to meet these stringent requirements, enabling the next generation of quantum foundations research.

Research Requirement6CCVD Material RecommendationTechnical Advantage
High-Purity Optical LatticesOptical Grade Single Crystal Diamond (SCD)SCD offers superior purity and low birefringence, minimizing absorption and scattering losses for the high-intensity lasers (689 nm) used for Raman transitions and optical lattices. This is critical for maintaining atomic coherence.
Integrated Atom Chip SubstratesHigh-Quality Polycrystalline Diamond (PCD)For large-area integration of micro-fabricated components (e.g., magnetic coils for the $10^{-2}$ T field), our PCD wafers provide unmatched thermal conductivity, ensuring stable operation and minimizing thermal drift in the sensitive interferometer.
Integrated Electronics/ElectrodesBoron-Doped Diamond (BDD)BDD can be used for highly stable, chemically inert electrodes or integrated sensors within the vacuum environment, offering precise control over electric fields if required for future extensions of the setup.

The complexity of atomic interferometers often requires custom geometries and integrated functionalities that standard silicon or sapphire cannot support. 6CCVD provides tailored solutions to accelerate experimental realization:

  • Custom Dimensions: We offer PCD plates/wafers up to 125mm in diameter, ideal for large-scale vacuum chamber integration or complex optical lattice setups.
  • Precision Thickness Control: We supply SCD and PCD in thicknesses ranging from 0.1 ”m to 500 ”m, allowing researchers to optimize substrates for specific thermal loads or optical path lengths.
  • Advanced Metalization: The integration of magnetic coils or electrodes for precise field control is crucial. 6CCVD offers in-house custom metalization using materials including Au, Pt, Pd, Ti, W, and Cu, enabling the fabrication of high-performance atom chips directly on the diamond substrate.
  • Ultra-Smooth Polishing: Our SCD polishing achieves Ra < 1nm, and inch-size PCD achieves Ra < 5nm. This ultra-smooth surface quality is essential for minimizing scattering losses when diamond is used as an optical window or waveguide platform.

6CCVD’s in-house PhD team specializes in applying MPCVD diamond to demanding quantum and high-power applications. We provide expert consultation on material selection, thermal modeling, and integration strategies for projects involving Atomic Interferometry, Optical Lattices, and High-Precision Quantum Sensing. Our global shipping capabilities (DDU default, DDP available) ensure rapid delivery of custom materials worldwide.

Call to Action: For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The canonical quantum formalism predicts that the interference pattern registered in multislit experiments should be a simple combination of patterns observed in two-slit experiments. This has been linked to the validity of Born’s rule and verified in precise experiments with photons, nuclear spins, nitrogen-vacancy centers in diamond, and large molecules. Due to the expected universal validity of Born’s rule, it is instructive to conduct similar tests with yet other physical systems. Here we discuss analogs of triple-slit experiment using atoms allowing tripod energy level configuration, as realizable, e.g., with alkaline-earth-metal-like atoms. We cover all the stages of the setup including various ways of implementing analogs of slit blockers. The precision of the final setup is estimated and offers improvement over the previous experiments.