Guest lecture 3 - Qubit to Quantum Computer
Study online at https://quizlet.com/_6shpy4
1. IBM research and quantum computing: - first few decades about how we take
bits and mix that with quantum mechanics and compute that
- figure out how to build them
2. Classical bits: coded on phone and computer by transistors and can be viewed
as a switch. If off then (0) and if on (1)
3. Qubit (4): - the state of a qubit, can be an arbitrary point on the surface of a
sphere
- the (0) is at the north pole and the (1) at the south pole.
- the state of a qubit is therefore defined by two angles like longitude and latitude
- 50% you'll measure 0 or 1, the state is a combination of 0 and 1 and is known as
a superposition
4. Quantum bit difference (2): - if qubit at equator, 50% it is 0, 50% it is 1
- when measured there is a different bit stream of 0s and 1s
11010100
5. What should you do when computing with a qubit?: you should decide which
state's probability you want close to 1 and which closer to 0
6. What is the outcome of measurement in qubit?: The qubit state reflects the
probability with which we measure 0 or 1 respectively
7. Can u remeasure a qubit?: no, once the first measurement is done of a qubit,
the following states will remain the same.
8. What happens if you have multiple qubits? (both on equator) (2): - if 2 qubits
are both on the equator you have 4 possibilities occuring at the same time (25%
chance)
- there are (0, 0) (0, 1) (1, 0) (1, 1)
9. How do u determine the number of states of a qubit?: qubit = 2^n states
10. Scaling in qubit:
11. Classical logic (2): - irreversible
1 bit gates
ID, NOT
2 bit gates
AND, NAND, OR, NOR, XOR, XNOR
12. Quantum logic (2): 1 bit gate
IDENTITY
BITFLIP (flips pr(0) and pr(1)
1/4
Study online at https://quizlet.com/_6shpy4
1. IBM research and quantum computing: - first few decades about how we take
bits and mix that with quantum mechanics and compute that
- figure out how to build them
2. Classical bits: coded on phone and computer by transistors and can be viewed
as a switch. If off then (0) and if on (1)
3. Qubit (4): - the state of a qubit, can be an arbitrary point on the surface of a
sphere
- the (0) is at the north pole and the (1) at the south pole.
- the state of a qubit is therefore defined by two angles like longitude and latitude
- 50% you'll measure 0 or 1, the state is a combination of 0 and 1 and is known as
a superposition
4. Quantum bit difference (2): - if qubit at equator, 50% it is 0, 50% it is 1
- when measured there is a different bit stream of 0s and 1s
11010100
5. What should you do when computing with a qubit?: you should decide which
state's probability you want close to 1 and which closer to 0
6. What is the outcome of measurement in qubit?: The qubit state reflects the
probability with which we measure 0 or 1 respectively
7. Can u remeasure a qubit?: no, once the first measurement is done of a qubit,
the following states will remain the same.
8. What happens if you have multiple qubits? (both on equator) (2): - if 2 qubits
are both on the equator you have 4 possibilities occuring at the same time (25%
chance)
- there are (0, 0) (0, 1) (1, 0) (1, 1)
9. How do u determine the number of states of a qubit?: qubit = 2^n states
10. Scaling in qubit:
11. Classical logic (2): - irreversible
1 bit gates
ID, NOT
2 bit gates
AND, NAND, OR, NOR, XOR, XNOR
12. Quantum logic (2): 1 bit gate
IDENTITY
BITFLIP (flips pr(0) and pr(1)
1/4
