Pulse-level control for quantum resource preparation

TL;DR

This paper introduces a pulse-level control technique for quantum state preparation in transmon qubits, optimizing electromagnetic pulses to efficiently generate entangled states and reduce control complexity.

Contribution

It presents a novel method for minimal-time quantum state preparation using optimized pulses targeting quantum correlations directly, improving efficiency over traditional gate-based approaches.

Findings

Achieves maximal entanglement in Bell, GHZ, and W states.

Reduces control complexity in quantum algorithms.

Demonstrates faster state preparation with optimized pulses.

Abstract

Minimizing the time required for quantum state preparation is crucial to mitigate decoherence and enable practical quantum algorithms on near-term hardware. In this work, we introduce a technique for quantum state preparation in transmon-qubit systems using optimized electromagnetic pulse sequences rather than discrete quantum gates. By directly targeting quantum correlations instead of specific target states, we identify minimal-time pulse protocols that optimize relevant entanglement resources, such as concurrence and the three-tangle for two and three qubit systems, respectively. For the figures of merit considered, this approach successfully achieves maximal entanglement in each case: Bell, GHZ and W like states. Beyond state preparation, the resource-oriented nature of the approach leads to a reduced effective expressivity of the control scheme, a feature that represents an advantage in algorithmic settings where excessive control freedom is known to hinder performance.