# Qubit gates using hyperbolic secant pulses

## TL;DR

This paper demonstrates the use of hyperbolic secant pulses to implement microwave-driven Z-gates on superconducting transmon qubits, exploiting their unique properties for detuning-controlled phase operations.

## Contribution

It experimentally shows hyperbolic secant pulses enable detuning-controlled phase gates, offering a new method for microwave-driven quantum gate implementation.

## Key findings

- Hyperbolic secant pulses perform cyclic evolution regardless of detuning.
- They can induce phase shifts without changing state populations.
- First demonstration of microwave-driven Z-gates with a single control parameter.

## Abstract

It has been known since the early days of quantum mechanics that hyperbolic secant pulses possess the unique property that they can perform cyclic evolution on two-level quantum systems independently of the pulse detuning. More recently, it was realized that they induce detuning- controlled phases without changing state populations. Here, we experimentally demonstrate the properties of hyperbolic secant pulses on superconducting transmon qubits and contrast them with the more commonly used Gaussian and square waves. We further show that these properties can be exploited to implement phase gates, nominally without exiting the computational subspace. This enables us to demonstrate the first microwave-driven Z-gates with a single control parameter, the detuning.