Descripción del proyecto
El teorema de Lee-Yang llega al ámbito cuántico para describir sistemas cuánticos de muchos cuerpos
El teorema de Lee-Yang brinda una descripción de las transiciones de fase y las propiedades analíticas de las ecuaciones termodinámicas a partir de la distribución de ceros de la función de partición. Los ceros de Lee-Yang ya no son solo un concepto teórico; recientemente se han identificado a partir de mediciones de observables fluctuantes, lo que ofrece una perspectiva completamente nueva de las transiciones de fase en sistemas de muchos cuerpos que interactúan entre sí. El proyecto financiado con fondos europeos QuLeeYang ampliará la teoría de Lee-Yang más allá de los sistemas de equilibrio clásicos. Se formulará una teoría unificadora de las transiciones de fase en sistemas cuánticos de muchos cuerpos que interactúan entre sí desde la perspectiva de los ceros de Lee-Yang y se utilizarán dispositivos cuánticos diseñados para corroborar las predicciones sobre las transiciones de fase. Los resultados del proyecto tendrán repercusiones de calado para el procesamiento de la información cuántica y la termodinámica cuántica.
Objetivo
Over the last years, investigations of Lee-Yang zeros – complex zeros of the partition function for systems of finite size – have become an indispensable theoretical tool in equilibrium statistical physics with diverse applications, ranging from protein folding and percolation to complex networks and magnetism. In the thermodynamic limit, the Lee-Yang zeros approach the real value of the control parameter for which a phase transition occurs. Despite these developments, surprisingly little attention has so far been devoted to applications of Lee-Yang theory beyond classical equilibrium systems. One reason may be that Lee-Yang zeros (being complex values of physical quantities) for years were seen as a purely theoretical concept with little relevance to experiments. However, this view has recently been contested by several experiments, in which Lee-Yang zeros have been determined. A novel cumulant method allows for the determination of Lee-Yang zeros from measurements of fluctuating observables, thus offering a completely new perspective on phase transitions in interacting many-body systems. Here, building on this cumulant method, I propose to formulate a unifying theory of phase transitions in interacting quantum many-body systems, including space-time, dynamical, and quantum phase transitions, from the perspective of Lee-Yang zeros. I will connect this theoretical framework to large-deviation statistics, fluctuation relations, and many-body entanglement in non-classical systems. Furthermore, I will devise experimental schemes to test my predictions and, in particular, investigate quantum phase transitions in engineered quantum devices. Fulfilling these objectives will expand the field far beyond its current state-of-the-art and potentially result in major scientific breakthroughs with important implications for other research fields, such as quantum information processing and quantum thermodynamics.
Ámbito científico
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MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinador
02150 Espoo
Finlandia