From October 2000 to September 2001, the author had the opportunity to visit the National Institute of Standards and Technology (NIST) in Boulder, Colorado, USA. This period was both a valuable research experience and a personal journey. Boulder, located near the Rocky Mountains at an altitude of about 1600 meters, is known for its high living standards and strict policies to maintain a high quality of life, though this has led to high land prices. The author stayed in an apartment near NIST for about a year before moving due to renovations. NIST, one of the nation's key research institutions, celebrated its 100th anniversary this year. It employs over 3200 staff and approximately 1600 guest researchers, with most researchers based in Gaithersburg, Maryland. The Boulder branch has around 400 employees and a relaxed atmosphere. The campus is lush with greenery, making it ideal for lunch breaks, but lacks sports facilities. NIST has its own police force that enforces strict speed limits and conducts security checks, which were particularly stringent during times of heightened tensions, such as the Iraq War. The author joined the High-Temperature Superconductivity (HTSC) group led by Dr. Ronald H. Ono, focusing on high-frequency devices. Despite the challenges of being a guest researcher, the author successfully developed an edge-junction YBCO Josephson junction for use in high-frequency mixers, contributing to the group's research. The division also houses five other groups, including those studying cryo-electronics and magnetic devices, which were unexpectedly reorganized during the author's stay. weekly Friday evening social gatherings at the bar fostered a relaxed and open environment, where researchers and staff could discuss both professional and personal matters. The author found the lack of formal hierarchy in English, similar to the casual nature of Japanese, particularly appreciated. While the author enjoyed the freedom to focus on research, they noted that NIST staff often handle numerous administrative tasks. However, the efficient use of time by American researchers was a valuable lesson. Overall, the experience provided a unique insight into American research environments and methodologies, which the author deeply appreciated.From October 2000 to September 2001, the author had the opportunity to visit the National Institute of Standards and Technology (NIST) in Boulder, Colorado, USA. This period was both a valuable research experience and a personal journey. Boulder, located near the Rocky Mountains at an altitude of about 1600 meters, is known for its high living standards and strict policies to maintain a high quality of life, though this has led to high land prices. The author stayed in an apartment near NIST for about a year before moving due to renovations. NIST, one of the nation's key research institutions, celebrated its 100th anniversary this year. It employs over 3200 staff and approximately 1600 guest researchers, with most researchers based in Gaithersburg, Maryland. The Boulder branch has around 400 employees and a relaxed atmosphere. The campus is lush with greenery, making it ideal for lunch breaks, but lacks sports facilities. NIST has its own police force that enforces strict speed limits and conducts security checks, which were particularly stringent during times of heightened tensions, such as the Iraq War. The author joined the High-Temperature Superconductivity (HTSC) group led by Dr. Ronald H. Ono, focusing on high-frequency devices. Despite the challenges of being a guest researcher, the author successfully developed an edge-junction YBCO Josephson junction for use in high-frequency mixers, contributing to the group's research. The division also houses five other groups, including those studying cryo-electronics and magnetic devices, which were unexpectedly reorganized during the author's stay. weekly Friday evening social gatherings at the bar fostered a relaxed and open environment, where researchers and staff could discuss both professional and personal matters. The author found the lack of formal hierarchy in English, similar to the casual nature of Japanese, particularly appreciated. While the author enjoyed the freedom to focus on research, they noted that NIST staff often handle numerous administrative tasks. However, the efficient use of time by American researchers was a valuable lesson. Overall, the experience provided a unique insight into American research environments and methodologies, which the author deeply appreciated.