343339
After several years working as a member of the Technical Staff at Bell Laboratories ( BTL ) at Murray Hill , NJ , developing an ultrasonic amplifier , a mechanism invented by Dr. D.L. White , Tsu moved to the IBM , T.J. Watson Research Center in Yorktown Heights , NY as an associate to Dr. Leo Esaki beginning a well-known collaboration that yielded a theory of man-made quantum materials , superlattice s and quantum wells .
 Bell Laboratories, Tsu, Dr. Leo Esaki
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Bell Laboratories, Tsu, Dr. Leo Esaki