CAREER: Entanglement Engineering in Dissipation-Driven Quantum Systems

Non-technical Abstract

Quantum information processing (QIP) has rapidly emerged as a compelling research direction, driven by the prospect of quantum computers capable of performing calculations that are too large for any current or conceivable future classical (non-quantum) supercomputer. The Achilles heel of QIP has been dissipation, the friction that both generates heat and destroys the long-lived quantum correlations among quantum bits ("qubits") necessary for QIP, so far limiting quantum information systems in both size and complexity.

Such correlations among qubits are called "entanglement," and a goal of this research is to produce any desired entangled state of qubits, which becomes the starting point for a quantum computation.

A powerful approach to address this general problem is quantum reservoir engineering: the idea is to turn the tables on dissipation and use it as a resource for steering a quantum system, such that the dissipation-driven dynamics naturally relax the system to the state of interest. This CAREER project supports basic research into developing a novel reservoir engineering framework and leverages it for entanglement generation in noisy quantum systems.

From a practical standpoint, this will help identify critical milestones for establishing reservoir engineering as a standard paradigm for scalable and robust entanglement generation, which has applications in all areas of quantum information science, including quantum computing, sensing and communication. In addition, the proposed research will enable fundamental advances in the physics of quantum systems coupled to a noisy environment by developing theoretical tools to rigorously explore the validity of standard dissipative models in the presence of noise that varies, and is correlated, in time.

The education and training aspect in this project will assume a multi-pronged approach that will expose graduate and undergraduate students to a wide variety of analytical and computational techniques in quantum information and quantum optics. Aided and informed by close connections with experimental realizations of solid-state qubits, the aim will be to provide the trainees a holistic view of the polyglot field of QIP and address the strategic national need to create a "quantum-smart" workforce.

The training aspect will be integrated with broad educational and outreach goals via new and continuing curriculum and course development initiatives, public talks, and promoting open access venues for communicating research results. Technical Abstract

Quantum reservoir engineering is an attractive approach for correcting errors and realizing stable quantum coherences autonomously. The basic idea is to tailor the dissipative environment of the target systems so that this engineered dissipation relaxes the system to and sustains it in a desired target state. While versatile, existing schemes for dissipative state preparation rely exclusively on time-independent dissipative dynamics, which can leave the protocols susceptible to unwanted spurious dissipation.

The PI's broad vision is that this project will enable a transformative new class of dissipative state preparation protocols with dramatically improved speed, fidelity and robustness to errors. To this end, the research will broadly focus on two directions: (i) study of dynamics driven by time-dependent dissipation, and (ii) study of dynamics driven by correlated dissipation.

These theoretical studies will involve developing a comprehensive analytical and numerical framework with some of the first explorations of the validity of open quantum systems descriptions, especially in a context where non-trivial dissipation is a useful resource. For instance, the outcomes of this project will address fundamental questions pertaining to implications of adiabaticity and non-Markovianity for reservoir engineering and provide useful pointers for quantum error correction and error mitigation in the presence of correlated noise.

This has transformative potential not only for the entanglement stabilization protocols envisioned here but also for any platform involving dynamic control of quantum systems. The PI maintains an active collaboration with experimental groups who will test the ideas on Josephson-junction-based superconducting platforms. Thus this research will complement and advance the rapidly growing experimental capabilities in quantum control of low-dimensional open systems in the near-term.

Further, it will help strengthen interdisciplinary connections between disparate fields of quantum information/quantum optics, optimal control and strongly-interacting field theories, all of which focus on far-from-equilibrium quantum dynamics.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.