本周准备《高温超导物理》讲义时偶然发现以下这篇纪念Jean Rossat-Mignod的文字。它出现在1994年M2S会议文集的卷首。我是1997年从北大一位充满理想主义气息的老师那里第一次听到Jean Rossat-Mignod这个名字的，当时这位老师的语气充满尊敬和惋惜。 尽管二十多年过去了，但当我的目光停留在下面这段话时，内心依然起了波澜

Jean was born in Albertville (France) in 1944. Inspired by the surrounding mountains, he knew how to choose the summits worth climbing,

Jean Rossat-Mignod 不仅开创了铜氧化物高温超导体自旋动力学行为的非弹性中子散射（INS）研究，而且在Neutron Scattering Study of the  System,【Physica C 185-189 (1991) 86-92】 这篇文章中为这一领域后续近二十年的研究确定了基调----自旋共振现象和赝能隙现象。有趣的是，这篇文章发现的所谓41 meV feature 曾经在相当长的一段时间里没有合理的解释，直到1995年一个来自Princeton的中子散射研究组确认其来自于d-波超导引起的自旋共振。相关文章是 Phonon and Magnetic Neutron Scattering at 41 meV in  【PRL,75,316(1995)】，P.W. Anderson 是这篇文章中唯一的理论学家。他们发现，自旋共振信号来源于d-波超导体中与自旋激发相关的BCS相干因子的放大效应。与此形成鲜明对比的是，这一相干因子在通常的s-波超导体中将抑制低能自旋激发。更直观地说，自旋共振信号的出现表明Cooper对在空间上具有非平庸的自旋关联结构。这一共振信号现在已经成为鉴别非常规超导体的标准判据。

需要说明的是，自旋共振信号因为是能谱中的一个sharp feature在很长一段时间里是铜氧化物高温超导机理研究关注的焦点。但是现在普遍认为这一特殊的信号是体系非常规超导的后果，而非原因。而Rossat-Mignod文章中另一个主题----赝能隙现象，虽然得到了大量研究，但是这些研究主要是通过其它手段进行的，而从非弹性中子散射这一直接视角的研究却非常有限。Rossat-Mignod如果在世，情况应该不同。2010年之后，随着共振非弹性X-射线散射(RIXS)技术的飞速进步，铜氧化物高温超导体自旋动力学行为研究的焦点逐渐由非弹性中子散射(INS)转向RIXS。但是INS和RIXS是两种互补的技术，尤其是INS所具有的大动量覆盖，高能量分辨的优势是RIXS短期内无法企及的。

由于法语发音的原因，我在很长一段时间里并不确定那位北大老师提到的名字就是Rossat-Mignod，而是从文献中消失的名字隐约做出这个判断的，直到我看到这篇纪念文字。又或许，这些年来这位科学英雄仍一直在阿尔卑斯山脚下优雅地用他的大玩具与自然对话吧，没有丝毫矫揉造作，直到我看到这篇纪念文字。

这篇纪念文字的具体出处是：

 Physica C: Superconductivity Volumes 235–240, Part 1, December 1994, Page xv， 这是M2S会议的会议文集，M2S会议是指International conference on Materials and Mechanisms of Superconductivity, 1994年的M2S会议在Grenoble举行，这里正是Jean Rossat-Mignod长期工作的地方，Rossat-Mignod的工作是这次会议的一个重要主题，可惜他已经无法参加。M2S会议曾于1997年和2018年两次在北京举行。

以下是这篇纪念文字的全文

Jean Rossat-Mignod ( 17.10.1944- 19.08.1993)

by J. Flouquet

The following obituary is in memory of Jean Rossat-Mignod, who drowned shortly after the International Conference on Strongly Correlated Systems (San Diego) on 19 August 1993. It is with regret that he is missed today at what would have been for him a major event in the context of his extensive study over the past five years of  by neutron scattering.

Jean was born in Albertville (France) in 1944. Inspired by the surrounding mountains, he knew how to choose the summits worth climbing, equipped with an originality of approach and supported by his large team of colleagues. For some of us, who lacked his expertise in the field of neutron scattering, it was not always easy to follow his tracks through the beauty of recriprocal space. However, it is to his credit that he convinced us of the power of this tool. He was an excellent guide, as well as a pioneer in the complex problem of strongly correlated systems. A fine example of his work was his demonstration of strong magnetic scattering in the cuprate superconductors and the occurrence of a pseudo-gap in their excitation spectrum.

Jean’s work covered all aspects of modern magnetism, starting in 1972 with his PhD thesis, “Investigation of the rare-earth oxysullides  ”. The scope of his work was illustrated in the symposium held in the auditorium of the Grenoble museum the day prior to the formal start of this Conference. The subjects covered were neutron scattering, magnetic structure, heavy fermions, superconductivity and f electrons, low-density carrier systems, low dimensionality, and the cuprates. Jean’s contribution to all of these fields was substantial.
We will remember Jean for his enthusiasm, his strong will, and for his rigorous scientific work. For many of us who knew him and his wife Marcelle, we will remember their warm hospitality and our times spent together in their nice house in Belmont at the base of the Belledone mountains.

上述文字改编自我地知乎主页文章《Jean Rossat-Mignod》