Table Of Contents

Previous topic

Composites

Next topic

Some further general-purpose modules from utils

Some general-purpose elements

Polarizable particles in optical fields

Mode

H_\text{mode}&=\omega\adagger a+i\lp\eta\adagger-\hermConj\rp\\
&\equiv-iz\adagger a+i\lp\eta\adagger-\hermConj\rp\equiv(-\delta-i\kappa)\adagger a+i\lp\eta\adagger-\hermConj\rp

where we have introduced

z\equiv\kappa-i\delta

type mode::Ptr
typedef boost::shared_ptr<const ModeBase> Ptr;
class Mode
const mode::StateVector mode::coherent(const dcomp& alpha, size_t cutoff)
const mode::StateVector mode::init(const mode::Pars&)
const mode::Ptr mode::make(const mode::Pars&, QM_Picture, const A&)
const mode::Ptr mode::make(const mode::ParsLossy&, QM_Picture, const A&)
const mode::Ptr mode::make(const mode::ParsPumped&, QM_Picture, const A&)
const mode::Ptr mode::make(const mode::ParsPumpedLossy&, QM_Picture, const A&)

template<typename A>

Particle in momentum space

H_\text{kinetic}=\frac{p^2}{2m}\equiv\omrec k^2

class particle::Spatial
fin_

governs the finesse of space resolution: \text{fin\_}=\log_2(\text{number of dimensions})

xMax_
deltaX_
kMax_
deltaK_

Rationale

(In the following discussion we assume \hbar=1.)

Spatial is a tool to facilitate state-vector representations in both X and P space, where the two are canonically conjugate operators, so that \comm{X}{P}=i, and hence the wave functions of two representations are linked with Fourier transformation. So for example, it can represent a single spatial degree of freedom.

Space is discretized (finite \Delta X) and limited (X=-X_\text{max}\dots X_\text{max}), with periodic boundary condition. From discrete space, it follows that momentum is limited (P=-P_\text{max}\dots P_\text{max}), while from limited space, it follows that momentum is discretized (finite \Delta P). The momentum operator is replaced by an operator K with integer spectrum: P=K\cdot\Delta P. When the kinetic term is expressed with this new operator K, the frequency \Delta P^2/(2m) appears, which is called recoil frequency.

From the fact that position & momentum are canonically conjugate, it follows that P_\text{max}\cdot\Delta X=\Delta P\cdot X_\text{max}=\pi. In Particle and the related interactions, \Delta P=1 by convention. From this it follows that X_\text{max}=\pi, P_\text{max}=N/2 and \Delta X=2pi/N, where N is the number of dimensions, that is, the resolution of space (equal to 2^\text{fin\_}).

When it comes to mode functions, it follows from the above that only 2\pi-periodic mode functions can be well represented in such a space, which do not contain Fourier components larger than P_\text{max}. Therefore, for example we can represent \sin(Kx),\;\cos(Kx),\;\exp(\pm iKx) with integer K not larger than P_\text{max}.

discuss intimacies of discrete Fourier transform...

Interactions

class JaynesCummings
class ParticleTwoModes2D

script: 1particle1mode

z cavity axis, x orthogonal direction

g pump mode function, f cavity mode function

1

H_\text{kinetic}^x+\sqrt{U_0\vclass}\lp g(x)\adagger+\hermConj\rp+H_\text{mode}

2

H_\text{kinetic}^z+U_0\abs{f(z)}^2\adagger a+\sqrt{U_0\vclass}\lp f(z)\adagger+\hermConj\rp+H_\text{mode}

3

H_\text{kinetic}^z+\vclass\abs{g(z)}^2+U_0\abs{f(z)}^2\adagger a+\sqrt{U_0\vclass}\lp f(z)g(z)\adagger+\hermConj\rp+H_\text{mode}

4

H_\text{kinetic}^z+\vclass\abs{g(z)}^2+U_0\abs{f(z)}^2\adagger a+H_\text{mode}

MultiLevel

class MultiLevel

Define multi-level systems (e.g. atoms with arbitrary level schemes) with various driving and loss schemes at compile time.

Other