v3.26.1
Cover - USD ($)
12 Months Ended
Mar. 31, 2026
Jun. 12, 2026
Sep. 30, 2025
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Mar. 31, 2026    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2026    
Current Fiscal Year End Date --03-31    
Entity File Number 001-42555    
Entity Registrant Name Quantumsphere Acquisition Corporation    
Entity Central Index Key 0002070900    
Entity Tax Identification Number 00-0000000    
Entity Incorporation, State or Country Code E9    
Entity Address, Address Line One 1185 Avenue of the Americas    
Entity Address, Address Line Two Suite 304    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10036    
City Area Code (212)    
Local Phone Number 612-1400    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Elected Not To Use the Extended Transition Period false    
Entity Shell Company true    
Entity Public Float     $ 82,468,800
Entity Common Stock, Shares Outstanding   11,406,650  
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Auditor Name CBIZ CPAs P.C.    
Auditor Location Morristown, NJ    
Auditor Firm ID 199    
Units, each consisting of one ordinary share and one right      
Title of 12(b) Security Units, each consisting of one ordinary share and one right    
Trading Symbol QUMSU    
Security Exchange Name NASDAQ    
Ordinary shares, par value $0.0001 per share      
Title of 12(b) Security Ordinary shares, par value $0.0001 per share    
Trading Symbol QUMS    
Security Exchange Name NASDAQ    
Rights, each right entitling the holder to receive one-seventh of one ordinary share      
Title of 12(b) Security Rights, each right entitling the holder to receive one-seventh of one ordinary share    
Trading Symbol QUMSR    
Security Exchange Name NASDAQ