:Leo Esaki

{{Infobox scientist

| name = Leo Esaki

| native_name = 江崎玲於奈

| native_name_lang = ja

| image = Leo Esaki 1959.jpg

| caption = Esaki in 1959

| birth_date = {{Birth date and age|1925|03|12|mf=yes}}[http://www.japanprize.jp/en/prize_prof_1998_esaki.html Dr. Leo Esaki]. japanprize.jp

| birth_place = Takaida-mura, Nakakawachi-gun, Osaka Prefecture,
Empire of Japan

| death_date =

| death_place =

| alma_mater = Tokyo Imperial University
(BSc, 1947; PhD, 1959)

| known_for = {{Plain list|

Discovering quantum tunnelling in semiconductors (1957)
Inventing the tunnel diode (1957)
Work on superlattices and quantum wells (1970)

}}

| title = IBM Fellow

| term = 1967–1992

| awards = {{Plain list|

}}

| honors = {{Plain list|

25px Order of Culture (1974)
25px Grand Cordon of the Order of the Rising Sun (1998)

}}

| fields = Solid-state physics

| work_institutions = {{Plain list|

Tokyo Tsushin Kogyo
(1947–1960)
Thomas J. Watson Research Center (1960–1992)

}}

Leo Esaki ({{Langx|ja|江崎玲於奈|Ezaki Reona}}; born March 12, 1925) is a Japanese solid-state physicist who shared the 1973 Nobel Prize in Physics with Ivar Giaever and Brian David Josephson for his work on quantum tunnelling in semiconductors, which led to his invention of the tunnel diode that exploits this phenomenon. His research was done when he was with Tokyo Tsushin Kogyo (now Sony). He has also contributed in being a pioneer of the semiconductor superlattices.

Early life and education

Esaki was born in Takaida-mura, Nakakawachi-gun, Osaka Prefecture (now part of Higashiōsaka City) and grew up in Kyoto. He attended Doshisha Junior High School, then the Third Higher School. After graduating, he studied physics at Tokyo Imperial University (now the University of Tokyo), where he attended Hideki Yukawa's course in nuclear theory. He experienced the Bombing of Tokyo while at university.江崎玲於奈『限界への挑戦―私の履歴書』（日本経済新聞出版社）2007年

Esaki received his BSc and PhD in 1947 and 1959, respectively, from the University of Tokyo (UTokyo).

Career

=Esaki diode=

File:GE 1N3716 tunnel diode.jpg for scale)]]

File:Leo Esaki 1959b.jpg

From 1947 to 1960, Esaki joined Kawanishi Corporation (now Denso Ten) and Tokyo Tsushin Kogyo (now Sony). Meanwhile, American physicists John Bardeen, Walter Brattain, and William Shockley invented the transistor, which encouraged Esaki to change fields from vacuum tube to heavily-doped germanium and silicon research in Sony. One year later, he recognized that when the PN junction width of germanium is thinned, the current-voltage characteristic is dominated by the influence of the tunnel effect and, as a result, he discovered that as the voltage is increased, the current decreases inversely, indicating negative resistance. This discovery was the first demonstration of solid tunneling effects in physics, and it was the birth of new electronic devices in electronics called Esaki diode (or tunnel diode), the first quantum electronic device invention in history. He received a doctorate degree from UTokyo due to this breakthrough invention in 1959.

In 1973, Esaki was awarded the Nobel PrizeEsaki, Leo, "Long Journey into Tunneling," [http://nobelprize.org/nobel_prizes/physics/laureates/1973/esaki-lecture.html Nobel Lecture], December 12, 1973. for research conducted around 1958 regarding electron tunneling{{Cite journal| first1 = L.| title = New Phenomenon in Narrow Germanium p-n Junctions| last1 = Esaki| journal = Physical Review| volume = 109| issue = 2| pages = 603| year = 1958 | doi = 10.1103/PhysRev.109.603|bibcode = 1958PhRv..109..603E }} in solids. He became the first Nobel laureate to receive the prize from the hands of the King Carl XVI Gustaf.

=Semiconductor superlattice=

Esaki moved to the United States in 1960 and joined the IBM T. J. Watson Research Center, where he became an IBM Fellow in 1967. He predicted that semiconductor superlattices will be formed to induce a differential negative-resistance effect via an artificially one-dimensional periodic structural changes in semiconductor crystals. His unique "molecular beam epitaxy" thin-film crystal growth method can be regulated quite precisely in ultrahigh vacuum. His first paper on the semiconductor superlattice{{cite journal|doi=10.1147/rd.141.0061|title=Superlattice and Negative Differential Conductivity in Semiconductors|year=1970|last1=Esaki|first1=L.|last2=Tsu|first2=R.|journal=IBM Journal of Research and Development|volume=14|pages=61–65}} was published in 1970. A 1987 comment by Esaki regarding the original paper notes:

"The original version of the paper was rejected for publication by Physical Review on the referee's unimaginative assertion that it was 'too speculative' and involved 'no new physics.' However, this proposal was quickly accepted by the Army Research Office...""This Weeks's Citation Classic", Current Contents No 28, July 13, 1987.

In 1972, Esaki realized his concept of superlattices in III-V group semiconductors, later the concept influenced many fields like metals, and magnetic materials. He was elected as a member into the National Academy of Engineering for contributions to the engineering of semiconductor devices in 1977. He also awarded the IEEE Medal of Honor "for contributions to and leadership in tunneling, semiconductor superlattices, and quantum wells"{{Cite web |title=IEEE Medal of Honor Recipients |website=Institute of Electrical and Electronics Engineers (IEEE) |url=http://www.ieee.org/documents/moh_rl.pdf|date=April 22, 2015|access-date=August 9, 2019|archive-url=https://web.archive.org/web/20150422004457/http://www.ieee.org/documents/moh_rl.pdf|archive-date=April 22, 2015}} in 1991 and the Japan Prize "for the creation and realization of the concept of man-made superlattice crystals which lead to generation of new materials with useful applications" in 1998.{{Cite web|url=https://www.japanprize.jp/en/prize_prof_1998_esaki.html|title=The Japan Prize Foundation|website=www.japanprize.jp|access-date=August 9, 2019}}

Esaki's "five don'ts" rules

In the 1994 Lindau Nobel Laureate Meetings, Esaki suggests a list of "five don'ts" which anyone in realizing his creative potential should follow. Two months later, the chairman of the Nobel Committee for Physics Carl Nordling incorporated the rules in his own speech.{{cite journal|doi=10.1088/0031-8949/1995/T59/001|bibcode=1995PhST...59...21N|url=https://web.stanford.edu/~rotundu/documents/how_to_get_it.pdf|title=How to get the Nobel Prize in physics|year=1995|last1=Nordling|first1=Carl|journal=Physica Scripta|volume=59|pages=21–25|s2cid=250817314 }}

Don't allow yourself to be trapped by your past experiences.
Don't allow yourself to become overly attached to any one authority in your field – the great professor, perhaps.
Don't hold on to what you don't need.
Don't avoid confrontation.
Don't forget your spirit of childhood curiosity.

Later years

Esaki moved back to Japan in 1992. Subsequently, he served as president of the University of Tsukuba and Shibaura Institute of Technology. Since 2006, he is the president of Yokohama College of Pharmacy. Esaki is also the recipient of The International Center in New York's Award of Excellence, the Order of Culture (1974) and the Grand Cordon of the Order of the Rising Sun (1998).

After the death of Yoichiro Nambu in 2015, Esaki is the eldest Japanese Nobel laureate.

Recognition

In recognition of three Nobel laureates' contributions, the bronze statues of Shin'ichirō Tomonaga, Leo Esaki, and Makoto Kobayashi were set up in the Central Park of Azuma 2 in Tsukuba City in 2015.{{Cite web|url=http://mainichi.jp/feature/news/m20150316ddlk08040111000c.html|archive-url=https://web.archive.org/web/20150424074404/http://mainichi.jp/feature/news/m20150316ddlk08040111000c.html|url-status=dead|title=ノーベル賞:江崎、小林、朝永氏の銅像やレリーフ設置完成記念式でお披露目「子どもが夢を」−−つくば・中央公園／茨城 - 毎日新聞|archive-date=April 24, 2015|access-date=August 9, 2019}}

=Awards and honors=

List:

1959 – Nishina Memorial Prize
1960 – Asahi Prize
1961 – Stuart Ballantine Medal
1965 – Japan Academy Prize
1973 – Nobel Prize in Physics
1974 – Order of Culture
1985 – James C. McGroddy Prize for New Materials
1989 – Harold Pender Award
1991 – IEEE Medal of Honor
1998 – Japan Prize
1998 – Grand Cordon of the Order of the Rising Sun
2001 – Honorary Doctor at the Hong Kong University of Science and Technology
2007 – Honorary Distinguished Professor at the National Tsing Hua University

=Membership in learned societies=

1960 Fellow of the American Physical Society
Physical Society of Japan
1975 – Member, the Japan Academy
1976 – Foreign Associate, National Academy of Sciences
1977 – Foreign Associate, National Academy of Engineering
1989 – Member, Max Planck Society
1991 – Member, American Philosophical Society
1994 – Foreign Member, Russian Academy of Sciences
1995 – Honorary Foreign Member, Korean Academy of Science and Technology
1996 – Member, Accademia dei Lincei

Family

Esaki's daughter, Anna Esaki, is married to Craig S. Smith, former Shanghai bureau chief of The New York Times and China bureau chief of The Wall Street Journal.{{Cite news|date=January 14, 1990|title=Anna Esaki Wed To Craig S. Smith|language=en-US|work=The New York Times|url=https://www.nytimes.com/1990/01/14/style/anna-esaki-wed-to-craig-s-smith.html|access-date=August 19, 2021|issn=0362-4331}}

References

External links

{{Nobelprize}} including the Nobel Lecture, December 12, 1973 Long Journey into Tunnelling
[https://web.archive.org/web/20050117192748/http://www-03.ibm.com/ibm/history/history/year_1973.html IBM record]
IEEE History Center – Leo Esaki. Retrieved July 19, 2011 from [http://www.ieeeghn.org/wiki/index.php/Leo_Esaki Leo Esaki - Engineering and Technology History Wiki]
Sony History – The Esaki Diode. Retrieved August 5, 2003 from [https://web.archive.org/web/20030804052243/http://www.sony.net/Fun/SH/1-7/h5.html Sony Global | Sony History]
[http://www.vega.org.uk/video/programme/28 Freeview video 'An Interview with Leo Esaki' by the Vega Science Trust]