Open Positions

applications closed.

Call for Postdoctoral Fellow (Full-time Fixed-term Project Researcher)
at Department of Physics, Graduate School of Science, The University of Tokyo (UTokyo)

1. Job Title and Number of Persons:
Postdoctoral Fellow (Full-time Fixed-term Project Researcher), 1 person.
2. Term of Employment:
Starting Date: as soon as possible after April 1, 2022
The first contact will be ended on March 31, 2023 (due to Japanese fiscal year)
3. Renewal of Contract:
Employment may be renewed annually (up to March 31, 2024).
Renewal of the employment will be determined by taking into account budget status, assigned work progress, achievement at the end of work period, as well as attitudes in research activities.
4. Probationary Period:
6 months from the date of appointment
5. Work Location:
Graduate School of Science
7-3-1 Hongo Bunkyo-ku, Tokyo, Japan.
6. Affiliation:
Asai group, Department of Physics, Graduate School of Science.
7. Job description:
Our research goal is to realize Positronium (Ps) Bose-Einstein Condensation (BEC). Ps is the bound state of an electron and its antimatter positron. It is the lightest atom. BEC has not been realized yet for systems which contain antimatter. If Ps BEC is obtained, many interesting and important experiments be performed, e.g., antimatter gravity measurement and 511 keV gamma-ray laser development. The challenges are to cool Ps sufficiently and to obtain very high Ps density. New techniques are required and currently under study.
The successful applicant is expected to carry out research to realize Bose-Einstein condensation of positronium focusing mainly on one of the following in cooperation with our collaborators:
  • High-density positron beam generation.
  • Development of positronium generation, condensation, and cooling nanomaterials.
  • Laser cooling of positronium.
* This research will be carried out under the Japan Science and Technology Agency (JST) Fusion Oriented REsearch for disruptive Science and Technology (FOREST) project "Realization of a gamma-ray laser produced from antimatter quantum condensate" (2021—, FOREST Researcher: Dr. Akira Ishida)
8. Work Hours:
The UTokyo will adopt the Discretionary Labor System for this position. Appointee will be paid according to the pre-determined number of hours, i.e., 7 hours 45 minutes per day, or 38 hours 45 minutes per week, instead of actual work hours.
9. Holidays and Leaves:
Saturdays, Sundays, Public holidays of Japan, Year-end and New Year holidays (December 29 through January 3).
Appointee will be able to use Annual paid leave, Special paid leave, etc.
10. Salary and Benefits:
Postdoctoral fellows as defined in the "Regulations Concerning Employment of Specified Fixed-term Faculty Members" of the University of Tokyo. Annual salary system is adopted, and appointee will be paid about 300 000-400 000 JPY per month including performance-based bonus (depending on the appointee's ability, performance and experience).
Appointee may be able to have commuting allowance (up to 55 000 JPY per month) if the payment conditions are satisfied.
11. Insurance:
Enrolled in an employment and health insurance provided by Ministry of Education, Culture, Sports, Science and Technology (MEXT) Mutual Aid Association, as required by law.
12. Eligibility:
Persons with Ph. D or equivalent degree are considered to be eligible. Those who are expected to obtain Ph. D by the time of appointment are also considered.
13. Application Documents:
1) Curriculum Vitae.
The standard CV format of the UTokyo can be downloaded ( ) and used if needed.
2) Research experience.
3) Publication list (indicate up to 3 most significant publications and specify their URL or DOI information accessible over the Internet).
4) Research plan.
5) Two recommendation or reference letters.
14. Application Submission:
Applicants should send the above application documents (1–5 in PDF format) as E-mail attachments to with the subject "Application for Postdoctoral fellow". The recommendation or reference letters should be sent directly by those who write the letters to the same E-mail address.
(If you do not receive a reply within a few days, please be sure to contact us to confirm.)
15. Application Deadline:
Friday January 7, 2022.
16. Selection:
Successful candidates will be selected by an interview after passing a pre-screening based on the application documents. It is possible to have the interview remotely.
17. Inquiries:
Dr. Akira Ishida, Department of Physics, Graduate School of Science, The University of Tokyo.
Telephone : +81-3-3815-8384
E-mail :
18. Job Posting:
The University of Tokyo
19. Others:
Personal information received through this application process will not be used for any other purposes.
Applications from women, as well as from those who have foreign nationality, are strongly encouraged for this position as per "Declaration of Gender Equality Acceleration" of The University of Tokyo (March 3, 2009). Special considerations will be given to those who have specific conditions on the work environment.