**Quantum Epistemology: "Experiments are the only means of (real) knowledge at our disposal. The rest is poetry, imagination"**

--Max Planck

--Max Planck

__Photoelectric effect__is the basis for ARPES (Angle-Resolved Photoelectron Emission Spectroscopy) technique we employ in our researchEinstein, Albert (1905).

Annalen der Physik. 17 (6): 132-148.

Albert Einstein "for his services to Theoretical Physics, and especially for his discovery of the law of the __photoelectric effect__".
--> **Nobel Prize in Physics (1921)**

Experimental observation of photoelectric effect dates back in 1887 when Heinrich Hertz discovered that electrodes illuminated with ultraviolet light create electric sparks more easily.

Further development of the technique was made by Kai M. Siegbahn winning another prize for the __photoelectric effect__
--> **Nobel Prize in Physics (1981)**

**Condensed Matter Physics:**

**Specific heat of solids [Einstein model of phonon modes in crystalline solids]**

Einstein, Albert (1906).

Annalen der Physik. 4. 22: 180-190.

**Bose-Einstein condensates [basis for superfluidity, superconductivity and more]**

Einstein, Albert (1925).

Sitzungsberichte der Preussischen Akademie der Wissenschaften. 1: 3.

**tried hard on topological effects ....**

Einstein, Albert (XXXX).

Topological-Order:

Quantum entanglement (short or long-range) and Aharonov-Bohm effect is at the heart of topological order.

**Einstein-Podolsky-Rosen**(Phys. Rev. 47, 777 1935) paper was from their IAS Princeton days but it is not clear if they believed in the physical reality of entanglement.

Aharonov-Bohm effect/phase, Quantum entanglement and topological-order (including SPTs) are interrelated in a fundamental way.

__von Neumann__,

__Weyl__and

__Einstein__were among the earliest members of IAS having office at Princeton campus during their first few years.

Quantum entanglement led to new questions on

**epistemology**...

Also see

**Weyl returns**