4003
An efficient , defect - enabled spin amplifier based on a non - magnetic semiconductor , Ga ( In ) NAs , is proposed and demonstrated , with a large spin gain ( up to 2700 % at zero field ) for conduction electrons and a high cut - off frequency of up to 1 GHz .
 Chemical: Ga ( In ) NAs
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Ga ( In ) NAs