Holographic deep thermalization for secure and efficient quantum random state generation

Abstract

Quantum randomness, especially random pure states, underpins fundamental questions like black hole physics and quantum complexity, as well as in practical applications such as quantum device benchmarking and quantum advantage certification. The conventional approach for generating genuine random states, known as ‘deep thermalization’, faces significant challenges, including scalability issues due to the need for a large ancilla system and susceptibility to attacks, as demonstrated in this work. We introduce holographic deep thermalization, a secure and hardware-efficient quantum random state generator. Via a sequence of scrambling-measure-reset processes, it continuously trades space with time, and substantially reduces the required ancilla size to as small as a system-size-independent constant; at the same time, it guarantees security by eliminating quantum correlation between the data system and potential attackers. Thanks to the resource reduction, our circuit-based implementation on IBM Quantum devices achieves genuine 5-qubit random state generation utilizing only a total of 8 qubits. The deep thermalization technique is a promising approach to generate genuine random states from partial quantum measurements, but is experimentally challenging. This work introduces a secure, hardware-efficient variant which requires only a constant number of ancilla qubits, and demonstrates it on the IBM Quantum devices.