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This project aims to build a quantum computer emulator from scratch, including all the mathematical foundations that supports a quantum computer.
Since I'm using my own module for handling complex numbers it will be extremely
inefficient. However, having a complex matrix object with methods such as
is_hermitian() or normalize() allows us to easily understand the
underlying math in quantum computing.
- Python3
- PLY Used for the lexical and syntactic analyzer of the quantum computer assembly language.
- PrettyTables (optional) for cool printing of complex matrices.
Run pip3 install -r requirements.txt to install requirements.
From the root of the project type python3 qsimulator/qparse.py. This starts
a quantum computer with 16 registers of 9 qubits and prompts a shell expecting
instructions.
You can call STATUS from a shell to see the current internal values of the quantum registers and quantum variables. Note that this is not the same as calling the instruction MEASURE. The status instruction will display the current status of the quantum computer including the matrix representing the quantum state of its registers without affecting its internal state.
Obviously, we can only do it because we are emulating the quantum computer, this wouldn't be possible with a real quantum system.
As per the current release only the initialize and select instructions are implemented.
The instruction INTIALIZE RN [01..01] will initialize the Nth register to
the given bitstring. If you don't provide a bitstring it will be initialized
with zeros.
Example: INITIALIZE R6 [100010001] will initialize R6 to the identity matrix.
Note that when the quantum computer is started all its quantum registers are in a uninitialized status. Trying to access an uninitialized register will cause an exception.
It can be discussed whether this uninitialized behavior is a good choice or not. My guess is that future real quantum computers would still need a big amount of energy to start and maintain a register so it makes sense to force programmers to explicitly initialized the registers when they need it.
SELECT V RN X Y Puts Y qubits from the Nth register into the variable V
starting from X
Example:
INITIALIZE R0 [010010011]
SELECT MYVAR R0 3 6
MYVAR will contain qubits of R0 from 3 to 9.
[qparse] >>> STATUS
Quantum Computer with 16 registers of 9 qbits
====== Registers ======
R0:
+---+---+---+
| 0 | 1 | 0 |
| 0 | 1 | 0 |
| 0 | 1 | 1 |
+---+---+---+
R1...R15: Not initialized
====== Variables ======
MYVAR:
+---+---+---+---+---+---+
| 0 | 1 | 0 | 0 | 1 | 1 |
+---+---+---+---+---+---+
Not implemented yet
Not implemented yet
Not implemented yet
Not implemented yet
Most of the concepts used are extracted from the book Quantum computing for Computer Scientists by Noson S. Yanofsky and Mirco A. Mannucci.
Both Quantum Computing since Democritus and its lecture notes by Scott Aaronson were of big help to understand quantum mechanics and an invaluable source of inspiration
If you are, like me, just a computer scientist without any clue about physics but you really want to understand all this sh*t I'd encourage you to start by reading Decoding the Universe by Charles Seife. This book makes a gently introduction to modern physics from an information theory perspective.