QLC: EAGER: Harnessing molecular conformational dynamics for electromechanical qubits

传统计算机的基本信息单位是位。它可以存在于两种状态中的一种，这两种状态通常被称为“开”和“关”状态，或者1和0。量子计算机是不同的。量子计算机的基本信息单位是量子位。然而，与传统计算机中的比特不同，量子位可以存在于许多不同的状态，这为构建能够彻底改变科学和技术的强大计算机提供了可能性。然而，创造量子比特是具有挑战性的，而且它们通常只能在非常低的温度下持续存在。因此，实现量子计算的变革潜力需要量子比特在室温下同时稳定，并且可以精确地操纵和测量。在化学系大分子、超分子和纳米化学项目的支持下，匹兹堡大学的Daniel Lambrecht教授和Geoffrey Hutchison教授正在研究一种新型分子量子比特，这种量子比特可以在更温暖的温度下工作，与现有系统相比，它的寿命更长。该项目的发现可能会促进室温量子计算的“量子飞跃”，这可能对材料设计、药物发现、机器学习、安全通信等产生广泛影响。这项工作为包括高中、本科和研究生在内的多个层次的学生创造了研究和培训机会。重要的是，这项工作培养了化学和量子信息科学跨学科交叉的学生，这对于能够充分利用量子计算能力的STEM劳动力至关重要。本项目采用理论与计算相结合的方法，结合实验验证，研究了碗状分子（如“buckybowl”corannulenes和sumanenes）的电场门控反演作为分子机电量子比特的实现。这些“纳米碗量子位”有可能克服当前一代机电量子位的局限性，特别是由于内部缺陷或量子位浴相互作用而对超低（mK）低温操作和退相干的要求。具体来说，它们：(i)与当前一代悬浮碳纳米管相比，量子到经典转变的温度提高了100倍以上；（ii）与当前类型的机电量子比特相比，减少了量子比特与环境的偶极相互作用，从而将相干寿命提高了10倍以上；（iii）可以在纳米电子学中实际可实现的电场强度下运行。这些特性解决了当前机电量子比特的主要缺点。研究问题包括：1)纳米碗反转模式的高零点能量是否能显著促进更高温度的运行？2)纳米碗量子比特之间的预测纠缠有多强？它们的退相干寿命是多长？解决这些问题将导致纳米碗作为机电量子比特的原理验证探索，其可能比当前一代好几个数量级。理论/实验反馈回路用于验证计算预测并在必要时改进计算方法。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The basic unit of information in a conventional computer is the bit. It can exist in one of two states, which are often called 'on' and 'off' states, or ones and zeros. Quantum computers are different. The basic unit of information in a quantum computer is the qubit. However, unlike the bit in conventional computers, qubits can exist in many different states, which gives rise to the possibility of building powerful computers that can revolutionize science and technology. However, creating qubits is challenging and oftentimes they persist only at very low temperatures. Thus, realizing the transformative potential of quantum computing requires qubits that are simultaneously stable at room temperature and can be precisely manipulated and measured. With support from the Macromolecular, Supramolecular, and Nanochemistry program in the Division of Chemistry, Professors Daniel Lambrecht and Geoffrey Hutchison at the University of Pittsburgh are studying a new type of molecular qubit that could operate at much warmer temperatures and with much longer lifetimes when compared to current systems. The project's discoveries could facilitate a 'quantum leap' toward room temperature quantum computing that could have broad implications for materials design, drug discovery, machine learning, secure communications, and more. This work creates research and training opportunities for students at multiple levels, including high school, undergraduate, and graduate. Importantly, this work trains students at the interdisciplinary intersection of chemistry and quantum information science, as is crucially needed for a STEM workforce that can fully utilize the power of quantum computing.This project employs theory and computation in tandem with experimental validation to study the electric-field gated inversion of bowl-shaped molecules such as "buckybowl" corannulenes and sumanenes as realizations of molecular electromechanical qubits. These "nanobowl qubits" have the potential to overcome limitations of current generation electromechanical qubits, specifically the requirement for ultra-low (mK) cryogenic operation and decoherence due to internal defects or qubit-bath interactions. Specifically, they: (i) offer greater than 100x increased temperatures for the quantum-to-classical transition, as compared e.g. to current generation suspended carbon nanotubes, (ii) reduce qubit-environment dipolar interactions and thereby enhance coherence lifetimes by more than 10x compared to current types of electromechanical qubits, and (iii) can be operated at electric field strengths realistically achievable in nanoelectronics. These characteristics address the main drawbacks of current electromechanical qubits. Research questions include: 1) Does the high zero-point energy of the nanobowl inversion mode facilitate significantly higher temperature operation? 2) How strong is the predicted entanglement between nanobowl qubits and what is their decoherence lifetime? Addressing these questions is giving rise to a proof of principle exploration of nanobowls as electromechanical qubits that are potentially orders of magnitude better than the current generation. A theory/experiment feedback loop is used to validate computational predictions and refine computational approaches, if necessary.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.