Monday, February 11, 2013

Israel Senitzky and Coherent/Glauber States

Here are a few quick notes on what might become my next history of physics presentation.  Does anyone know more about the history of Dr. Senitzky and coherent states?

I'm still studyinng for my quantum II pre-midterm this week.  Looking for more material on quantum operators, I performed a search for quantum operators in the American Jouranl of Physics which led to an article about the harmonic oscillator wave packet.  Since harmonic oscillators are one of the favorite subjects in both of my quantum classes, I and II, I read on.  The author, Saul Epstein of the University of Nebraska, mentioned that while several authors covered the Gaussian wave packet as an example of a wave function that will not change shape in a harmonic oscillator potential well,  I. R. Senitzky[2] (picture 1) had shown using the Schrodinger formalism that there were actually an infinite number of such non-shape changing packet wave functions.

Switching over to Dr. Senitzky's article, in the Physical Review[3], I began to pick up on the fact that what were called non-shape changing wavefunctions in 1954 we now call coherent, or Glauber states.  My interest was further piqued by the fact that Senitzky was working at the Signal Corps Engineering Laboratories in Fort Monmouth, New Jersey, the same place where my dad went to Signal Corp school when he was in the Army in the '60s.  Curious as to why Glauber states had been worked in the Signal Corp in 1954, I quickly popped over to Glauber's article on coherent states[4] to see if he referenced Senitzky.  He did not.  As an aside, Glauber's article is excellent!  It has a very nice review of  quantum electrodynamics in the first few sections.

I then did an internet search on Dr. Senitzky.  Other than a few interesting tidbits of trivia, (see below), all I could find was that in the early 1950's he served as what appears to have been an adminstrative reviewer of the Columbia Radiation Laboratory, (CRL) for the Signal Corps.  The reference I found didn't mention Senitzky doing any science at all.

The Interesting Stuff and Questions
A second review of Senitzky's article, turned up the acknowledgement of Julian Schwinger shown below (picture 2)

While the Senitzky's article didn't discuss QED or QFT at all, Schwinger was instrumental in both these fields.  A review of Senitzky's other papers between 1945 and 1960[5] turns up a number of papers about the interaction of electrons and quantum effects in electromagnetic fields and spontaneous emission.  In the late 1950's his work turned mostly towards masers.  Interestingly, masers were developed at the CRL in the early 50's, during the same time period that Senitzky was responsible for reviewing the lab.  A review of the coherent states article on Wikipedia turned up the diagram and caption shown to the left (picture 3).  In 1961, two years before Glauber's article, Senitzky published an abstract in Proceedings of the 15th annual Frequency Control Symposium that mentions

"...the noise temperature due to spontaneous emission
can be made much smaller than [hbar omega over k] while adequate gain is maintained."

Was Senitzky doing theoretical work on masers as early as 1954?  The main focus of CRL at the time was supposed to be magnetron tubes and it's obvious from some of Senitzky's papers that he was working on those.  Magnetrons, however, do not employ coherent wave packets.  The only record I can find of his activities right now indicates that his interest in CRL and their maser program was purely administrative.  This all raises a number of questions.

1.  Just for historical interest, how did Senitzky come to be working for the Army Signal Corps?  What was his role there?

2.  How was he associated with Schwinger?  Was it through the MIT Radiation Laboratory, (another military radar lab)?

3.  Was Senitzky in fact doing theoretical maser coherent state work?

4.  Why wasn't he referenced in Glauber's article?

Interesting Trivia and Addendums
Glauber would go on to win the Nobel prize for his work in 2005[9].

Senitzky was a boy prodigy violinist who received a scholarship to Julliard at the age of 13[7].

Senitzky's daughter was an MD who pioneered the treatment of menopause using testosterone and was featured in People magazine[8].











Picture of the Day:

From 2/11/13

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