Pulse programming

Pulse programming in experimental physics refers to the generation and control of electromagnetic waveforms with programmable frequency, phase, and amplitude. It originated in the context of nuclear magnetic resonance (NMR) during the 1970s^[1] and has since found widespread use in fields such as quantum information science, including electron spin resonance (ESR), trapped ions, quantum dots, and various superconducting qubit systems using Josephson junctions.

History and Applications

In early NMR systems, pulse sequences were implemented using analog hardware and timing circuits that could only generate fixed patterns. With the advent of direct digital synthesis (DDS) and programmable field-programmable gate arrays (FPGAs), modern pulse programming allows for complex, precisely timed sequences controlled via personal computers.^[2]

Pulse programming is a key technique in:

• Controlling qubits in NMR-based quantum computers.^[3]
• Generating and timing microwave pulses in superconducting and trapped-ion quantum systems.
• Executing dynamic decoupling and error correction sequences in experimental platforms.

Technical Implementation

Modern pulse programmers typically consist of:

• DDS modules to produce radiofrequency or microwave signals.
• FPGA boards that coordinate timing, gating, and synchronization.
• A software layer (often written in Python) that defines pulse sequences at a high level.

Precise control on the nanosecond scale is required in quantum experiments to avoid decoherence and gate errors.^[2]

Open Source Pulse Programming

Several open-source pulse programming systems have been developed to support quantum research:

Paul Pham's MIT System

An early open-source pulse programming system was created by Paul Pham as part of his master's thesis at MIT under Isaac Chuang. It was first deployed in Rainer Blatt's University of Innsbruck group and later used by:

• Tobias Schaetz’s quantum simulation group at the Max Planck Institute of Quantum Optics and University of Freiburg
• Piet Schmidt’s quantum metrology group at PTB
• Boris Blinov’s ion trap lab at the University of Washington
• Hartmut Haeffner’s group at University of California, Berkeley
• Tilman Pfau’s quantum optics group at the University of Stuttgart
• Andrew Drewson’s ion trap group at the University of Aarhus

The FPGA-based sequencer board and DDS waveform generators were eventually phased out, with some labs designing custom DDS boards compatible with the original system.^[4]

ARTIQ

The Advanced Real-Time Infrastructure for Quantum physics (ARTIQ) is a modern open-source control system developed by M-Labs in collaboration with the Ion Storage Group at NIST.^[5]

• ARTIQ uses a Python-based compiler and runtime system to generate real-time code for FPGAs.
• It supports precise control of lasers, microwaves, and triggers for quantum experiments.
• It is used by institutions such as NIST, UMD, and Oxford Ionics.

See Also

• Quantum computing
• Nuclear magnetic resonance
• Qubit
• Direct digital synthesis
• FPGA
• Josephson junction
• Python (programming language)