Super Cool Science:
An Exploration of Modern Experiment

Sarah Kaiser
Carlo Bradac, Mattias Johnsson, Matthew van Breugel, Ben Baragiola, Rochelle Martin, Mathieu L. Juan, Gavin Brennen, Thomas Volz

Department of Physics and Astronomy, Macquarie University

ARC Centre for Engineered Quantum Systems

Macquarie University logo EQuS logo

What do we want to know?

Energy level diagram for NV centers

Cooperative behavior of NV in Nanodiamonds

Energy level diagram for NV centers
Centers must be indistinguishable
  1. spatial: $V << \lambda^3$
  2. spectral
  3. spin manifold

Modeling Cooperative Effects

How to describe cooperation?

Dicke States

$|J,M\rangle =\sqrt{\frac{(J+M)!(J-M)!}{(2J)!}}\sum_{perm}|\underbrace{111...}_{\text{J+M}}\underbrace{000...}_{\text{J-M}}\rangle$
$N$ # of two-level emitters
$J=\frac{N}{2}$ total spin for the collective system
$M\in\{-J,J\}$ projection of the spin state, J+M excited emitters


R H Dicke [doi:10/cbq3mc]

Example: Dicke States

$M,~N=3$
3/2 $|111\rangle$
1/2 $|110\rangle+|101\rangle+|011\rangle$
−1/2 $|100\rangle+|010\rangle+|001\rangle$
−3/2 $|000\rangle$

What degrades superradiance?

(Local) Distinguishability.

  • spin–spin coupling
  • local phononic environments
  • localized charge fields
  • lattice stress/strain
  • etc.

Distinguishable = Dephasing

Energy level diagram for NV centers

Superradiance model parameters

  1. Domain Size: max # of cooperating centers
  2. Initial state of system
  3. Bright/dark decay rates
  4. Local dephasing rates

C Bradac et al. [arXiv:1608.03119]

Observations

Decay rates for excitations

Energy level diagram for NV centers

Comparing rates to model:

Model fits for SR data

Initial state exploration

g2^{bar}(\tau) measurements

Extensions: Low temp

  1. # of cooperating centers : ✖
  2. Initial state of system : ➖
  3. Bright/dark decay rates : ?
  4. Local dephasing rates : ✔?
    B. B Prasanna Venkatesh, M L Juan,
    O Romero-Isart [arXiv:1705.07847]



Extensions: Low temp








Reliability

Hardware reliability

Next unit of computing
guts of nuc

Practical tools need:

  • NO LICENCE SERVERS: Open source
  • Documentation: Community developed tools
  • Version controllable: Git or similar

Example: Package control and device setup


######################################################
# Install apps using Chocolatey
######################################################
Write-Host "Installing Chocolatey"
iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))
Write-Host

Write-Host "Installing applications from Chocolatey"
cinst 7zip.install anaconda3 arduino ConEmu firefox `
    git.install git-annex googlechrome putty ruby sublimetext3 vcxsrv visualstudiocode -y
Write-Host

Summary:

Done:

  • Ultrafast radiative lifetimes $\approx1\text{ns}$
  • Photon correlations consistency check model
  • Design hardware configurations/test control for new cryostat
  • Data collection and storage framework setup

To Do:

  • Temperature dependance of superradiance?
  • Expand model: Dipole dipole interactions
  • Super absorption?
  • Full experimental automation