- #1
rwooduk
- 762
- 59
ive been revising all holidays, unfortunately I've just realized I've been finding eigenvalues using the ensemble when i may have to change basis for the exam. looks at homework questions, workshop questions... nothing!
anyway an example problem:
rewrite
|PSI> = a|0> + b|1>
in the basis
|phi1> = a|0> + b|1>
|phi2> = b*|0> + a*|1>
my attempt
im assuming that to change basis you need to use the identity operator with the new basis, in this case
I = |phi1><phi1| + |phi2><phi2|
so I|PSI> = |PSI>
which looks a bit strange to me.
ANOTHER example
write:
|PSI> = 1/SQRT2 (|0> + |1>)
in the basis:
|3> = SQRT(1/3) |0> + SQRT(2/3) |1>
|4> = SQRT(2/3) |0> + SQRT(1/3) |1>
my attempt
I = |3><3| + |4><4|
I|PSI> = |PSI>
Please could someone confirm my method is correct before i make an *** of it in the exam. any help once again appreciated!
anyway an example problem:
rewrite
|PSI> = a|0> + b|1>
in the basis
|phi1> = a|0> + b|1>
|phi2> = b*|0> + a*|1>
my attempt
im assuming that to change basis you need to use the identity operator with the new basis, in this case
I = |phi1><phi1| + |phi2><phi2|
so I|PSI> = |PSI>
which looks a bit strange to me.
ANOTHER example
write:
|PSI> = 1/SQRT2 (|0> + |1>)
in the basis:
|3> = SQRT(1/3) |0> + SQRT(2/3) |1>
|4> = SQRT(2/3) |0> + SQRT(1/3) |1>
my attempt
I = |3><3| + |4><4|
I|PSI> = |PSI>
Please could someone confirm my method is correct before i make an *** of it in the exam. any help once again appreciated!