Physics Does Digital Optimization: for Machine Learning, Control Theory, Back Propagation, etc.
Eli Yablonovitch & SriKrishna Vadlamani
Electrical Engineering and Computer Sciences Dept
UC Berkeley
Abstract: Optimization is vital to Engineering, Artificial Intelligence, and to many areas of Science. Mathematically, we usually employ steepest-descent, or other digital algorithms. But, Physics itself, performs optimizations in the normal course of dynamical evolution. Nature provides us with the following optimization principles:
- The Principle of Least Action;
- The Variational Principle of Quantum Mechanics;
- The Principle of Minimum Entropy Generation;
- The First Mode to Threshold method;
- The Principle of Least Time;
- The Adiabatic Evolution method;
- Quantum Annealing
In effect, Physics can provide analog machines which solve digital optimization problems much faster than any digital computer. Of these physics principles, “Minimum Entropy Generation” in the form of bistable analog electrical or optical circuits is particularly adaptable toward offering digital Optimization. For example, we provide the analog electrical circuit which can address the challenging Ising problem, binary magnet energy minimization.
Bio: Prof. Yablonovitch introduced the idea that strained semiconductor lasers could have superior performance due to reduced valence band (hole) effective mass. With almost every human interaction with the internet, optical telecommunication occurs by strained semiconductor lasers.
He is regarded as a Father of the Photonic BandGap concept, and he coined the term 'Photonic Crystal'. The geometrical structure of the first experimentally realized Photonic bandgap, is sometimes called “Yablonovite”.
In his photovoltaic research, Yablonovitch introduced the 4(n squared) (“Yablonovitch Limit”) light-trapping factor that is in worldwide use, for almost all commercial solar panels.
His mantra that 'a great solar cell also needs to be a great LED”, is the basis of the world record solar cells: single-junction 29.1% efficiency; dual-junction 31.5%; quadruple-junction 38.8% efficiency; all at 1 sun.
His cellphone antenna company, Ethertronics Inc., has shipped over 2 billions antennas.
To find out more about Prof. Yablonovitch, you can consult his research web page.
Cette conférence est présentée par le RQMP Versant Nord du Département de physique de l'Université de Montréal et de Génie physique de la Polytechnique.
