Note-note is a prototype circuit for a reversible logic quantum computer controller test circuit.
Description
Some qubit types are controlled by exposing them to microwave waveforms, such as specific waveforms for X, Y, Z, and CNOT operations. If repetitions of these waveforms is created at room temperature as one or more prime line waveforms in the figure below (6 — single numerals in parenthesis will be explained below), a qubit can be controlled by the address line (AL) bus switching a waveform on an off at appropriate times (7), as shown.
The behavior is like a piano. The prime line waveform is like a piano string, always giving the same tone. The circuit that drives the AL bus is the pianist, digitally enabling the analog tone created by the string. The quantum computer program would be equivalent to the sheet music.
The reversible circuit contains three shift registers, each holding a measure of music. They are loaded with note note, rest note, and note rest in the test circuit.
The black graphics in the figure above are a flowchart, and the reversible circuit’s behavior follows the flowchart. The clock on each shift register is stopped except when it is the active box in the flowchart (4). When a box is active it shifts is contents, which is music, to the AL bus, gating the prime line and causing an operation on the qubit (5).
When the measure of music is fully transmitted, a control signal (2) goes through a diamond to another measure of music. Only one diamond can be active at once, so the two diamonds are controlled by a single decision signal (blue) (1) from the room temperature control computer. The decision might be based on whether or not a quantum error has occurred or not.
Circuit output
The simulation code produces several plots, one of which is very similar to the images in the pdf file below. The purple circled numerals correspond to single digits in parenthesis in the text above, such as (1) to (7).
Additional information
For those interested in maintaining this page, the Word and PowerPoint source of the figures can be downloaded.
As a docx
PPT
PPTX
Code and References
Simulation code is in the circuit file nn.cir in the github repository https://github.com/erikdebenedictis.
[REFERENCE TBD] This text to be a reminder to EPD to put a link to a document with a more detailed description. This could be Classical Reversible Logic Circuits for Quantum Computer Control, Zettaflops, LLC Technical Report ZF010, once I get around to posting the doc.