Phaser_STFT_Pulsegen

Development of an STFT (short time fourier transform) pulse-generator architecture for the Phaser hardware.

(Block diagram is subject to change)

Overview

A general purpose digital quantum computer needs to perform operations with multiple qbits. In a trapped ion system the qbits are represented by energy levels of an ion electron. For a multi ion quantum gate the electrons state needs to be entangled with the state of the electron in another ion. This can be achieved by coupling the electrons to a shared motional (vibrational) mode of the ions. In order to do so, the ions need to be exposed to a modulated driving field, the shape of which might be easily specified with a few parameters in frequency space. This would result in a faster, scalable and more elegant solution than driving the field with a precomputed waveform played back on an AWG.

Discussion and Prototypes

There have been a number of discussions on the topic. An outline of the architecture is drafted in the STFT pulsegen prototype notebook.

A (very raw) exemplification of some DFT and time-domain relations is given in Shape and Tone FFT.

Pulse leakage shows some spectral leakage effects of a time-limited signal.

Development

The architecture will be deployed on the Phaser hardware of the Sinara ecosystem and will eventually be controlled through Artiq.

It will be developed in migen FHDL and the intent is to build parameterizable and scalable code. Cores to be developed:

• FFT
• Half-band filters
• CIC filter
• DDS
• Artiq communication