LEFT JOIN LATERAL conditions and JSONB
jsonb_populate_record can't be used like a table as it only returns a scalar values. 

I think you want 

select id, (jsonb_populate_record(null::schrodinger, mt.jb_column -&gt; 'schrodinger')).* 
from my_table mt


If the json value doesn't contain the key schrodinger then this will automatically return null

Online example