is the director of Physics & Informatics Laboratories (PHI Labs), NTT Research, Inc. He is also Professor (Emeritus) at Stanford University and

National Institute of Informatics The is a Japanese research institute located in Chiyoda, Tokyo, Japan. NII was established in April 2000 for the purpose of advancing the study of informatics. This institute also works on creating systems to facilitate the spread of scienti ...

(Tokyo).

Biography

Yamamoto was born in

Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and List of cities in Japan, largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, ...

on November 21, 1950. In 1973 he received his B.S. degree from

Tokyo Institute of Technology is a national research university located in Greater Tokyo Area, Japan. Tokyo Tech is the largest institution for higher education in Japan dedicated to science and technology, one of first five Designated National University and selected as ...

. He continued his studies at

the University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...

where he received his M.S. in 1975 and Ph.D. in 1978. From 1978 to 1992, he worked at NTT Basic Research Laboratories in Tokyo. Since 1992, he has been a professor of applied physics and electrical engineering at Stanford University in the United States and currently a professor (emeritus). Since 2003, he also has been a professor at

in Tokyo and currently a professor (emeritus). In 2019, he became a founding director of NTT PHI Labs in Silicon Valley, California, the United States.

Work

Yamamoto's scientific focuses in the 1980s were coherent optical fiber communications, optical amplifier repeater systems, photon number squeezing in semiconductor lasers, quantum non-demolition (QND) measurements and other experimental and theoretical

quantum optics Quantum optics is a branch of atomic, molecular, and optical physics dealing with how individual quanta of light, known as photons, interact with atoms and molecules. It includes the study of the particle-like properties of photons. Photons have ...

subjects. Some of Yamamoto's key works from this era are proposals for how to physically realize photon-number squeezing, QND measurement, and a gate model quantum computer using single atoms and photons. His most prominent work in the 1990s is in semiconductor

cavity quantum electrodynamics Cavity quantum electrodynamics (cavity QED) is the study of the interaction between light confined in a reflective cavity and atoms or other particles, under conditions where the quantum nature of photons is significant. It could in principle be u ...

(especially involving microcavities and quantum wells) and quantum transport effects in mesoscopic devices. During the 2000s, his most important work was on the development of optically-active quantum dots as a platform for quantum information processing (both as

single-photon source Single-photon sources are light sources that emit light as single particles or photons. These sources are distinct from coherent light sources (lasers) and thermal light sources such as incandescent light bulbs. The Heisenberg uncertainty principl ...

s and as hosts for spin qubits.) Another important work was on exciton-polariton condensation effects. Yamamoto was also active in the development of security theory and realization of quantum key distribution protocols. Landmark papers from this era include the demonstration of indistinguishable photons from a single quantum dot; the proposal for biexciton cascade emission as a method for generating entangled photons from a single quantum dot (this is the proposal underlying essentially all QD entangled-photon sources, such as those reviewed in ), and control of a single spin qubit in a quantum dot using optical pulses. During the 2010s, his work has continued on exploring quantum dots as a platform for building both quantum repeaters and quantum computers. One highlight was the co-first demonstration (with Ataç İmamoğlu's group at

ETH (colloquially) , former_name = eidgenössische polytechnische Schule , image = ETHZ.JPG , image_size = , established = , type = Public , budget = CHF 1.896 billion (2021) , rector = Günther Dissertori , president = Joël Mesot , a ...

) of entanglement between a spin in a quantum dot and a photon emitted by it. Work on

exciton-polariton In physics the Exciton–polariton is a type of polariton; a hybrid light and matter quasiparticle arising from the strong coupling of the electromagnetic dipolar oscillations of excitons (either in bulk or quantum wells) and photons. Because lig ...

s continued. Since 2012, Yamamoto has studied the required number of physical qubits and expected computational time in a gate-model fault-tolerant quantum computer and pioneered the development of a novel quantum/classical hybrid computer, called coherent Ising machine inspired by developments in digital coherent optical communications and degenerate

optical parametric oscillator An optical parametric oscillator (OPO) is a parametric oscillator that oscillates at optical frequencies. It converts an input laser wave (called "pump") with frequency \omega_p into two output waves of lower frequency (\omega_s, \omega_i) by mean ...

Awards

Yamamoto is a fellow of the

Optical Society of America Optica (formerly known as The Optical Society (OSA) and before that as the Optical Society of America) is a professional society of individuals and companies with an interest in optics and photonics. It publishes journals and organizes conference ...

(now Optica), the American Physical Society, and the

Japan Society of Applied Physics (JSAP) is a Japanese group of researchers in the field of applied physics. JSAP originated in 1932 from a voluntary forum of researchers belonging to the University of Tokyo and the Institute of Physical and Chemical Research. During World War ...

. In 1985, Yamamoto received the Achievement Award of the Institute of Electronics, Information and Communication Engineers (IEICE) of Japan on his early work on coherent optical communications. In 1992, he received the Nishina Prize and the Carl Zeiss Award on his pioneering work on squeezed state generation in semiconductor lasers. In 2000, he received the IEEE LEOS Quantum Electronics Award and the Matsuo Science Prize. In 2005, he received the Medal of Honour with Purple Ribbon from the Government of Japan. In 2010, he was the Hermann Anton Haus Lecturer at MIT and gave a lecture on exciton-polariton condensation. In 2011, he received the Okawa Prize on his pioneering work on single photon generation from a quantum dot. In 2022, he received the Willis Lamb Award on his pioneering work on coherent Ising machines.

References

Nishina Memorial Foundation: Recipients of Nishina Memorial Prizes. https://www.nishina-mf.or.jp/project_en/kinen_en/ IEEE LEOS Quantum Electronics Award. https://www.photonicssociety.org/awards/quantum-electronics-award/quantum-electronics-award-award-winners Carl Zeiss Foundation: Recipients of Carl Zeiss Research Award. https://www.zeiss.com/corporate/int/innovation-and-technology/zeiss-research-award.html. ; ; ;

External links

* Yamamoto page at Stanford https://yoshihisayamamoto.sites.stanford.edu/ * Yamamoto page at NTT Research, Inc. https://ntt-research.com/phi/ {{DEFAULTSORT:Yamamoto, Yoshihisa 1950 births Living people Japanese expatriates in the United States Japanese physicists People from Tokyo Stanford University School of Engineering faculty Tokyo Institute of Technology alumni University of Tokyo alumni University of Tokyo faculty Nippon Telegraph and Telephone Fellows of the American Physical Society