Quantum Machine Learning course on Github

3D+1 Quantum Nonlocal Solitons with Gravitational Interaction


Nonlocal quantum fluids emerge as dark-matter models and tools for quantum simulations and technologies. However, strongly nonlinear regimes, like those involving multi-dimensional self-localized solitary waves (nonlocal solitons), are marginally explored for what concerns quantum features. We study the dynamics of 3D+1 solitons in the second-quantized nonlocal nonlinear Schroedinger equation. We theoretically investigate the quantum diffusion of the soliton center of mass and other parameters, varying the interaction length. 3D+1 simulations of the Ito partial differential equations arising from the positive P-representation of the density matrix validate the theoretical analysis. The numerical results unveil the onset of non-Gaussian statistics of the soliton, which may signal quantum-gravitational effects and be a resource for quantum computing. The non-Gaussianity arises from the interplay of the quantum diffusion of the soliton parameters and the stable invariant propagation. The fluctuations and the non-Gaussianity are universal effects expected for any nonlocality and dimensiona

All-Optical Scalable Spatial Coherent Ising Machine

Networks of optical oscillators simulating coupled Ising spins have been recently proposed as a heuristic platform to solve hard optimization problems. These networks, called coherent Ising machines (CIMs), exploit the fact that the collective nonlinear dynamics of coupled oscillators can drive the system close to the global minimum of the classical Ising Hamiltonian, encoded in the coupling matrix of the network. To date, realizations of large-scale CIMs have been demonstrated using hybrid optical-electronic setups, where optical oscillators simulating different spins are subject to electronic feedback mechanisms emulating their mutual interaction. While the optical evolution ensures an ultrafast computation, the electronic coupling represents a bottleneck that causes the computational time to severely depend on the system size. Here, we propose an all-optical scalable CIM with fully programmable coupling. Our setup consists of an optical parametric amplifier with a spatial light modulator (SLM) within the parametric cavity. The spin variables are encoded in the binary phases of the optical wave front of the signal beam at different spatial points, defined by the pixels of the SLM. We first discuss how different coupling topologies can be achieved by different configurations of the SLM, and then benchmark our setup with a numerical simulation that mimics the dynamics of the proposed machine. In our proposal, both the spin dynamics and the coupling are fully performed in parallel, paving the way towards the realization of size-independent ultrafast optical hardware for large-scale computation purposes.



Ph.D. course Quantum Machine Learning

Duration 20h (3CFU)
Scheduled at February or March 2022

1) introduction to phase space methods in quantum optics
2) introduction to quantum machine learning

1) Methods in the phase space, characteristic function
2) Gaussian states and their transformations
3) Neural network representation of Gaussian states
4) Training of quantum machine learning models
5) Examples
Gaussian Boson sampling
Neural networks variational ansatz for quantum many-body

Exam (two options)
1) Colloquium on theoretical aspects
2) Coding examples

Barnett and Radmore, Methods in Theoretical Quantum Optics

Configuring Emacs, the cool way

A super cool method to set the configuration of emacs, following DistroTube

Emacs requires tweaking the init.el file in the .emacs.d dir in home

init.el is written in emacs-lisp and a bit obscure to understand

One can use the wonderful emacs org-mode to code the init.el by using an auxiliary config.org placed in any directory

The steps are described below (generated by emacs org-mode)

In addition to set a proper configuration, it also useful to use emacs as a client, which speeds up running emacs.

This is done, first running the emacs daemon

/usr/bin/emacs --daemon

And then any time we launch emacs we use

emacsclient -c -a 'emacs'

In Linux systems, the emacs daemon can be launched at startup by adding the service to the systemd as detailed here

1 How to configure emacs by a emacsconfig.org file

1.1 Set your init.el in .emacs.d

Write the following init.el in .emacs.d


Here emacsconfig.org is the org configuration file with its path You can set any file

In this file we have various functions

  • Org Babel

Org Babel is a wonderful tool to use different languages in a single org file

  • org-babel-load-file

Loads Emacs Lisp source blocks in the org file

  • expand-file-name

Replace the file name with absolute path

  • user-emacs-directory

Is the directory where the Emacs-specific files are placed .emacs.d typically, where the search of the file starts

1.2 Write emacsconfig.org

In the .org file for the configuration we will write different parts as pieces of emacs lisp code. For example

#+begin_src emacs-lisp
(add-to-list 'default-frame-alist '(width . 180))
(add-to-list 'default-frame-alist '(height . 90))

#+begin_src emacs-lisp
(set-face-attribute 'default (selected-frame) :height 150)