Research-Low Temperature

Low Temperature Physics at Sussex, 1962-1990. Douglas Brewer

In addition to this reminiscence from Douglas, there is a separate page with pictures taken at his 90th birthday celebration on 25 July 2015.

My appointment to the University of Sussex was largely a matter of chance. Around six o’clock in the early autumn of 1961 I was standing outside the Clarendon Laboratory, Oxford, smoking a cigarette (no Health and Safety regulations then, but the experiments in my laboratory used potentially explosive liquid oxygen and liquid hydrogen). Roger Blin-Stoyle passed by on his way home and we engaged in casual conversation, during which he invited me home, a few hundred yards away, for a drink. During the course of a couple of stiff martinis he told me about Sussex and suggested that I might like to think about going there. At the age of thirty-six, with a wife and three children, it was time that I got a proper job instead of spending most of my time and energy as a Research Fellow with incidental lecturing and tutorial work, and so I went to see the University, talked to Ken Smith (the first Professor of Experimental Physics), then applied for a Senior Lectureship and had a more formal interview with him and Ted Shields, the Registrar, for whom I later developed a great admiration. Fortunately, my application was successful.

The only Science building at that time, the Physical Sciences building, later known as Physics and Mathematics I and now as Pevensey I, was intended at first to house Physics, Chemistry and Mathematics and, existing in a sea of mud, was far from completion. It had been designed by the Sir Basil Spence architects, whose vision of a physics or chemistry experimentalist seems to have been one of a troglodyte-type existence in a large hall with no need of windows. With the advent of actual people small slit windows were permitted, but even in the design of Physics and Mathematics II, which was occupied in 1967, relatively little was allowed to mar the brutalist architectural vision. (In the design of the Molecular Sciences (MOLS) Building, the robust attitude of Colin Eaborn, Professor of Chemistry since 1962 and founding Dean of MOLS, ensured a more user-friendly design).

Throughout 1962, the appointed Physics faculty members met at the Ship Hotel in Brighton, to discuss and agree the early stages curriculum and teaching courses. They did this while still carrying out their normal duties at their own Universities, who paid their salaries. (I have recently found out, through an article by Ted Shields in Falmer Magazine, Issue No.10, June 1986 that Sussex was the only one of the seven new Universities planned at that time to whom the Universities Grants Committee did not give funds to pay its newly appointed academic staff in these planning months before the formal opening of the Universities' teaching programmes.) In later years, we took on the many other tasks associated with creating a new University – in my case, to quote only one, becoming the first Faculty Treasurer of the Students' Union which in 1961-1962 had received a grant of £150 and had spent £200. That was actually quite fun – though sometimes exasperating – and when I gave it up several years later they presented me with a pewter mug with the quotation “natura non fecit saltum 1961-67” (slightly inaccurate – it should be “natura non facit saltus 1962-7”). I was touched, and I keep it together with the document that certifies that I am an Honorary Life Member of the Sussex University Students Union, which I hope is recorded somewhere in their archives.

The new University’s principles of undergraduate teaching were easy enough to agree with (with some reservations), but most physicists I knew had as their primary aim success in research. Their and their Universities’ reputations in the world depends more on that (in most cases at least) than on their teaching. In October 1962, there were, as I recall, seven [actually 12] Physics academic staff members with varied research interests, experimental and theoretical. Two of us, Sandy (A. D. C.) Grassie and I, were experimentalists whose work involved low temperatures, achieved with the use of liquid helium at about 270 degrees Centigrade below the freezing point of water. The point of using such low temperatures is that random thermal excitations (heat) are frozen out, and more organised quantum effects, which at ordinary temperatures are obscured by the thermal excitations, become observable. The field of low temperature Physics has revealed many unexpected phenomena, for example superconductivity in metals and superfluidity in the helium isotopes, helium-3 and helium-4. Many great physicists have been attracted to it, including Nobel Prize winners of whom our own theorist Tony Leggett is one.

Sandy’s interests were mainly in the electric and magnetic properties of solids, mine in liquid helium itself. Sandy's background was Aberdeen University and Cambridge; mine was Oxford and Ohio State University. In Spring 1963 we were joined by Low (A. L.) Thomson, who had been an undergraduate at St. Andrews University and gained a doctorate at Duke University, North Carolina; he came originally as a postdoctoral Research Assistant but a few years later became a Physics faculty member. I also had in 1962 a research student, Andrew Symonds, who had taken a top First Class Theoretical Physics degree at Oxford but bravely decided to come to Sussex to do experimental work (seduced, I suspect, by Roger Blin-Stoyle’s persuasive talk at a Finals Examination dinner in Wadham, his and Roger’s College at Oxford). This small group of people had not been planned as an embryonic Low Temperature Group, but it evolved into a major one over a few years by a process of self-selection, through the appointment of the best applicants for the academic physics posts that became available.

In 1963, the range of interest was extended by the arrival of Brian (B.L.) Smith, who had taken his doctorate at Queen Mary College, London on properties of liquefied rare gases (relatively high temperatures, 30K and above; the absolute zero is -273.15 degrees Centigrade) and had then done postdoctoral work in California. In the following few years the Clarendon Laboratory in Oxford provided three additional talented physicists – David (D.S.) Betts, Colin (C.B.P.) Finn and Mike (M.G.) Richards. The Clarendon had become, during the 1930s, a foremost world Low Temperature Laboratory through the immigration of three Jewish refugee physicists from Berlin – Franz Simon, Kurt Mendelssohn and Nicholas Kurti (the last was of Hungarian nationality); it was a great source to us of experienced low temperature faculty members – and also of postdoctoral Research Fellows and younger research students. David Betts had also spent time working in Ohio State in a group which was headed by John Daunt who was himself a product of the Clarendon. David’s main research interests were also in liquid helium and Mike Richards’ in the nuclear magnetic resonance behaviour of the light isotope of helium, helium-3. Mike had come direct from the Clarendon, as had Colin Finn who worked on paramagnetic salts at low temperatures. Colin gradually moved away from research and devoted his considerable talents to undergraduate teaching in which he was outstanding. Of the two remaining members of the Low Temperature Group, Mike (M.J.) Springford was also working on the low temperature properties of metals and alloys and John (J.W) Loram had done his doctorate work on the design and use of a highly sensitive differential calorimeter which he used in Sussex to measure the effect of small quantities of impurities on pure metals, in which he became an acknowledged expert. He later (around 1990) was drawn to the Cavendish Laboratory in Cambridge where he applied his differential calorimetry techniques to the then comparatively new field of “high temperature” superconductors – which means up to about the temperature of liquid nitrogen, 77K or around – 200 degrees C.

All this represents a very wide range of physics of the condensed state, and in what follows I shall confine myself mainly to my own research activities. However diverse the theoretical aspects, though, a great deal of the technical needs were common. Ken Smith, the first experimental Physics professor, had taken care of the basic general physics laboratory and workshop requirements, but there was need of facilities for cryogenic fluids, in particular liquid helium, a helium gas recovery system (the gas was very expensive and could not be allowed to escape) and myriad small but vital details for which no specialised technical staff help was available so we did it ourselves. All of this had to be started in the early months of 1962, together with planning of teaching activities and carrying out the jobs in our own Universities for which we were paid.

In these circumstances the choice of a specific research project was important but difficult. My research in recent years had been directed towards the behaviour of liquid helium-3 at very low temperatures, in particular whether it behaved as an “ideal fermi fluid”, and whether it became, like liquid helium-4, a superfluid at sufficiently low temperatures. Important theoretical principles were involved here, on which international opinion was deeply divided. At Ohio State University I had been privileged to be at the forefront of this work in establishing that liquid helium-3 did indeed behave like a fermi fluid at sufficiently low temperatures, and enabling its transition temperature to the superfluid state – if this existed – to be estimated from theory. At the Clarendon Laboratory in Oxford in 1959 to 1962 I was able to continue this work. But both of these laboratories possessed long established technical facilities and strong funding, based on hard won achievement. Neither of these, naturally, existed in Sussex. The aims were retained as long-term objectives but the immediate need was for simple, inexpensive experiments, which were still of fundamental interest.

I chose to return to the topic of my DPhil thesis twelve years earlier, namely the behaviour at low temperatures of adsorbed helium films. These have a thickness of 3 to 100 Angstrom units (in modern terminology 0.3 to 10 nanometres) and are easy to create and do fundamental experiments with. The aim was to have something significant published in a respected international journal within one year, and although that was not achieved the field developed into a fruitful one which has been contributed to, and independently developed, by many laboratories throughout the world. In Sussex, it helped to lead, through the discovery of surface magnetism in helium-3, to the award of the international triennial Fritz London Prize in Low Temperature Physics in 1999. (Fritz London was another German Jewish refugee, a theorist who spent a short time at the Clarendon before going on to Duke University, North Carolina for the rest of his career. He made profound contributions to the theories of superconductivity and superfluid helium-4, in particular the latter’s connection with Bose quantum statistics. His brother, Heinz, was an experimentalist who stayed in England and made important contributions to both theory and experiment. In particular, while working at AERE Harwell he invented the helium-3 dilution refrigerator which is now the basis of experimental work close to the absolute zero. The prototype of the high-power version of the refrigerator was later designed and developed at Sussex in collaboration with the Oxford Instrument Company who market it.)

In those early years the DSIR (Department of Scientific and Industrial Research) was very encouraging and helpful – for example, through visits by some of its top officials to gain personal information and give informal advice. Influential physicists from some of our great Universities were similarly sympathetic. As time passed the scope and sophistication of our work increased enormously and we attracted financial support from many agencies such as the US Army and Air Force (the US Office of Naval Research, in a special report on Low Temperature Physics in the UK, judged Sussex to be the foremost Laboratory). The Royal Society supported us through Protocols with the Science Academies of China, Russia, the Republic of Georgia. We received the first four Chinese LT visitors from China a year after the death of Mao Tse-tung, two of these as DPhil research students. We received a stream of high quality physicists who chose to come to Sussex for sabbatical leave, many of whom were leaders in their field, partly financed by our grants. These were mostly personal friends or acquaintances, such as Leon Cooper, a Nobel Laureate from Brown University, Rhode Island, whom I had worked with briefly in Columbus, Ohio, in 1958 (the University awarded him an Honorary DSc when he was here). We attracted to Sussex our own Nobel Laureate-to-be as a (semi) permanent faculty member, who came here, as he later said when he received our Honorary DSc, because of the theory group of Roger Blin-Stoyle and the experimental Low Temperature group. He went after a few years to the University of Illinois who had made him “an offer he couldn’t refuse,” but his Prize was for his work on the theory of superfluid helium-3 at Sussex.

In return for all these incoming benefits the LT Group contributed generously to the well-being of the physics community in the UK and internationally. Its faculty members, in addition to their own research publications, refereed and edited international journals and books, sat on Institute of Physics and Royal Society’s national and international committees (one of mine was the Royal Society’s National Committee for Physics, which I sat on as Chairman of the International Union of Pure and Applied Physics’ Very Low Temperature Commission). Many of our research students went on to become important members of the UK scientific community in, for example, Bristol, Cambridge, Keele, London, Manchester, Nottingham, Oxford. Others went on to high posts in industry. More recently, some went to work in the city and in banks, no doubt earning bonuses which in their impoverished student days would have kept their research laboratories going for years.

World War II had had a stimulating effect on Physics funding because of the contribution of physicists to the war effort, and the US Armed Forces had generously contributed small but important amounts to some of our Universities; all sources were bound to decline in time. The old DSIR underwent several metamorphoses of name and function – SRC (Science Research Council), SERC (E for Engineering) and more, and had become more remote; six other New Universities had come into being, some of them with strong Low Temperature Laboratories. “Relevance” was the rage, and curiosity-based research, in which you cannot calculate the outcome of your work, such as that which recently won a Nobel Prize for the discovery of graphene, was discouraged.

In the second half of the 1960s, however, the US National Academy of Sciences, recognising the scientific importance of the question of superfluidity in helium-3, set up a panel of prominent US low temperature physicists to look into the question of the optimum resources needed for research into it in terms of manpower, equipment and recurrent funds, and asked me to become a member. Based on the outcome of the panel’s work, I sent in a grant application which was not, as often happened, accepted in reduced form by the committee, but turned down flat with a personal letter from its Chairman, an eminent physicist whom I had know for many years – lamenting the fact that I was attempting to compete with the Americans and suggesting that I submit a small but quite original separate project of my own. This I was able to do, with some difficulty, in such a tortuous way as to make a small step in the direction of the superfluid helium-3 project. It helped later, after superfluidity had been discovered in Cornell in 1974, to make Sussex the first UK laboratory to achieve it. The Cornell physicists later received the Nobel Prize for their work.

The preceding paragraph, incidentally, is written not only as a partial outlet for paranoia, but also as an example of the sometimes malign effect that talented people in long-established institutions can have in lesser places. Another example seems to have been in an ambitious proposal for an Institute for Instrumentation in Optical Astronomy to be set up in Sussex, which I had to advocate when I became Chairman of Physics and Astronomy in 1967. Sussex was a natural place for it to be since Astronomy here had very distinguished staff with strong connections with the Royal Observatory in Herstmonceux; it would certainly have had a transformative effect on Sussex physics. During protracted meetings and negotiations I was aware of powerful forces operating in the background, but not aware of what their aims were, though I was much later given an inkling of them by our most distinguished astronomer at that time, Sir William McCrea. Eventually the proposal for Sussex collapsed and, I believe, was greatly modified and moved to Cambridge.

The Low Temperature Group continued strong and productive for many years until eventually catastrophe struck it, a catastrophe which started slowly in 1985. It was put to me then that the Royal Society felt that it was time, for reasons of international prestige, that the triennial International Conference on Low Temperature Physics should be held in the UK, and that Sussex was the place to hold it (previous such conferences in the UK had been held in Oxford in 1951, in London in 1962, in St. Andrews in 1975). Organising such conferences, with 1200 or more participants, is an extremely time-consuming and in many ways distasteful, occupation. I pointed out that the University of the person who spoke to me, which was Birmingham, had perfectly good conference facilities, but eventually, after seeking the opinion of my Low Temperature colleagues in Sussex and throughout the UK, it was agreed that Sussex should seek the nomination, and if successful would organise LT19 with the help of colleagues throughout the UK. The bid was, unfortunately, successful.

An early impediment appeared when the university, which had burnt its fingers with a recently held British Association Conference, refused to “host” the Conference – that is, to guarantee it any support in the way of free lecture theatres, finance, formal office assistance or other such arrangements. We had to transfer the location to the Metropole Hotel in Brighton, and financial control to the Institute of Physics, who did an excellent job of organisation and made, I believe, a handsome profit.

A more serious problem was the sudden – and to me, unexpected – secession of half of the LT faculty group. Mike Springford left to go to Bristol University; Sandy Grassie retired and taught physics at Roedean; John Loram took his almost unique differential calorimeter to the Cambridge high temperature superconductivity group; Mike Richards retired from Physics. These resignations created problems for the rest of us but we were, happily, reinforced by Mike Hardiman, a faculty member who had been appointed to John Venables’ Electron Microscopy Group a few years before. A talented and hard-working physicist, he played a significant part in the conference organisation and in liaison with the Institute of Physics.

The Conference ended, and was pronounced, as usual, to be immensely and probably unprecedentedly successful. So did Low Temperature Physics at Sussex: a brief, though bright, bubble. It went with a small bang, though it did whimper on for a few years as Low Thomsom and I made some small incursions into the low temperature excitations of “high temperature” superconductors, and a few more bright research students passed out into the community. Sic transit.

Douglas Brewer
January 2011